[Federal Register Volume 88, Number 82 (Friday, April 28, 2023)]
[Rules and Regulations]
[Pages 26382-26430]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08663]



[[Page 26381]]

Vol. 88

Friday,

No. 82

April 28, 2023

Part II





Environmental Protection Agency





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40 CFR Part 82





Protection of Stratospheric Ozone: Listing of Substitutes Under the 
Significant New Alternatives Policy Program in Refrigeration, Air 
Conditioning, and Fire Suppression; Final Rule

  Federal Register / Vol. 88 , No. 82 / Friday, April 28, 2023 / Rules 
and Regulations  

[[Page 26382]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2021-0836; FRL-6399-02-OAR]
RIN 2060-AT78


Protection of Stratospheric Ozone: Listing of Substitutes Under 
the Significant New Alternatives Policy Program in Refrigeration, Air 
Conditioning, and Fire Suppression

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Pursuant to the U.S. Environmental Protection Agency's 
Significant New Alternatives Policy program, this action lists certain 
substances as acceptable, subject to use conditions, in the 
refrigeration and air conditioning sector for chillers--comfort 
cooling, residential dehumidifiers, residential and light commercial 
air conditioning and heat pumps, and a substance as acceptable, subject 
to use conditions and narrowed use limits, in very low temperature 
refrigeration. Through this action, EPA is incorporating by reference 
standards which establish requirements for electrical air conditioners, 
heat pumps, and dehumidifiers, laboratory equipment containing 
refrigerant, safe use of flammable refrigerants, and safe design, 
construction, installation, and operation of refrigeration systems. 
Finally, this action lists certain substances as acceptable, subject to 
use conditions, in the fire suppression sector for certain streaming 
and total flooding uses.

DATES: This rule is effective May 30, 2023. The incorporation by 
reference of certain material listed in the rule is approved by the 
Director of the Federal Register as of May 30, 2023. The incorporation 
by reference of certain other material listed in the rule was approved 
by the Director of the Federal Register as of May 11, 2015 and 
September 7, 2018.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2021-0836. All documents in the docket are listed on the 
https://www.regulations.gov website. Although listed in the index, some 
information is not publicly available, e.g., Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. Certain other material, such as copyrighted material, is 
not placed on the internet and will be publicly available only in hard 
copy form. Publicly available docket materials are available 
electronically through https://www.regulations.gov or in hard copy at 
the Air and Radiation Docket, EPA/DC, EPA West, Room 3334, 1301 
Constitution Avenue NW, Washington, DC 20460. The Docket Center's hours 
of operations are 8:30 a.m.-4:30 p.m., Monday-Friday (except Federal 
Holidays). For further information on EPA Docket Center services and 
the current status, please visit https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Holly Tapani, Stratospheric Protection 
Division, Office of Atmospheric Protection (Mail Code 6205A), 
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, 
DC 20460; telephone number: 202-564-0679; email address: 
[email protected]. Notices and rulemakings under EPA's Significant 
New Alternatives Policy program are available on EPA's SNAP website at 
https://www.epa.gov/snap/snap-regulations.

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. General Information
    A. Executive Summary and Background
    B. Does this action apply to me?
    C. What acronyms and abbreviations are used in the preamble?
II. What is EPA finalizing in this action?
    A. Chillers--Listing of HFO-1234yf, HFC-32, R-452B, R-454A, R-
454B, and R-454C as Acceptable, Subject to Use Conditions, for Use 
in New Chiller Equipment Used in Comfort Cooling, Including Both 
Commercial AC and Industrial Process Air Conditioning (IPAC)
    1. Background on Chillers--Commercial AC and IPAC
    2. What are the ASHRAE classifications for refrigerant 
flammability?
    3. What are HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-
454C and how do they compare to other refrigerants in the same end-
use?
    4. Why is EPA finalizing these specific use conditions?
    5. What additional information is EPA including in these final 
listings?
    6. How is EPA responding to comments on chillers?
    B. Residential Dehumidifiers--Listing of HFO-1234yf, HFC-32, R-
452B, R-454A, R-454B, and R-454C as Acceptable, Subject to Use 
Conditions, for Use in New Residential Dehumidifiers
    1. Background on Residential Dehumidifiers
    2. What are the ASHRAE classifications for refrigerant 
flammability?
    3. What are HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-
454C and how do they compare to other refrigerants in the same end-
use?
    4. Why is EPA finalizing these specific use conditions?
    5. What additional information is EPA including in these final 
listings?
    6. How is EPA responding to comments on residential 
dehumidifiers?
    C. Non-Residential Dehumidifiers--Decision Not To Finalize the 
Proposed Listing of HFC-32 as Acceptable, Subject to Use Conditions, 
for Use in New Non-Residential Dehumidifiers
    1. Why is EPA not finalizing the proposal to list HFC-32 as 
acceptable, subject to use conditions, in new non-residential 
dehumidifiers?
    2. How is EPA responding to comments on non-residential 
dehumidifiers?
    D. Residential and Light Commercial AC and Heat Pumps (HPs)--
Revision of Use Conditions Provided in the Previous Listing of HFC-
32 as Acceptable for Use in New Self-Contained Room ACs and HPs
    1. Background on Self-Contained Room ACs and HPs
    2. What are the ASHRAE classifications for refrigerant 
flammability?
    3. What is HFC-32 and how does it compare to other refrigerants 
in the same end-use?
    4. What use conditions previously applied to this refrigerant in 
this end-use category?
    5. What updates to the use conditions is EPA finalizing?
    6. How do the updated use conditions differ from the previous 
requirements and why is EPA finalizing the change to the use 
conditions?
    7. What is the acceptability status of HFC-32 in self-contained 
room ACs and HPs?
    8. What additional information is EPA including in these final 
listings?
    9. How is EPA responding to comments on updating use conditions 
for HFC-32 in self-contained AC and HPs?
    E. Use Conditions and Further Information in Final Listings for 
Chillers, Residential Dehumidifiers, and HFC-32 Self-Contained Room 
ACs and HPs
    1. What use conditions is EPA finalizing and why?
    2. What additional information is EPA including in these final 
listings?
    3. How is EPA responding to comments on use conditions and 
further information for chillers, residential dehumidifiers, and 
HFC-32 self-contained room ACs and HPs?
    F. Very Low Temperature Refrigeration (VLTR)--Listing of R-1150 
as Acceptable, Subject to Use Conditions and Narrowed Use Limits, 
for Use in New VLTR
    1. Background on VLTR
    2. What is EPA's final listing decision for R-1150?
    3. What is R-1150 and how does it compare to other refrigerants 
in the same end-use?
    4. What use conditions is EPA finalizing?
    5. Why is EPA finalizing these specific use conditions?
    6. What narrowed use limits is EPA finalizing?
    7. Why is EPA finalizing these specific narrowed use limits?
    8. What additional information is EPA including in this final 
listing?

[[Page 26383]]

    9. How is EPA responding to comments on VLTR?
    G. Streaming and Total Flooding Fire Suppression--Listing of 2-
bromo-3,3,3-trifluoropropene (2-BTP) as Acceptable, Subject to Use 
Conditions, as a Streaming Agent in Non-Residential Applications and 
as a Total Flooding Agent in Normally Unoccupied Spaces Under 500 
ft\3\
    1. Background on Streaming and Total Flooding Fire Suppression
    2. What is EPA's final listing decision for 2-BTP?
    3. What is 2-BTP and how does it compare to other fire 
suppressants in the same end-uses?
    4. What use conditions is EPA finalizing?
    5. Why is EPA finalizing these specific use conditions?
    6. How is EPA responding to comments on 2-BTP?
    H. Total Flooding Fire Suppression--Listing of EXXFIRE[supreg] 
as Acceptable, Subject to Use Conditions, for Use in Normally 
Unoccupied Spaces
    1. What is EPA's final listing decision for EXXFIRE[supreg]?
    2. What is EXXFIRE[supreg] and how does it compare to other fire 
suppressants in the same end-use?
    3. What use conditions is EPA finalizing and why?
    4. How is EPA responding to comments on EXXFIRE[supreg]?
    I. Total Flooding Fire Suppression--Listing of Powdered Aerosol 
H (Pyroquench-[alpha]TM) as Acceptable, Subject to Use 
Conditions, for Use in Normally Unoccupied Spaces
    1. What is EPA's final listing decision for Powdered Aerosol H?
    2. What is Powdered Aerosol H and how does it compare to other 
fire suppressants in the same end-use?
    3. What use conditions is EPA finalizing and why?
    4. How is EPA responding to comments on Powdered Aerosol H?
    J. How is EPA responding to other comments?
III. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act and 1 CFR 
Part 51
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act (CRA)
IV. References

I. General information

A. Executive Summary and Background

    This action finalizes listings of new alternatives for the 
refrigeration and air conditioning (AC) and fire suppression sectors. 
Specifically, EPA is:
     Listing hydrofluoroolefin (HFO)-1234yf, hydrofluorocarbon 
(HFC)-32, R-452B, R-454A, R-454B, and R-454C as acceptable, subject to 
use conditions, for use in chillers used in comfort cooling, including 
commercial AC and industrial process AC (IPAC);
     Listing HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-
454C as acceptable, subject to use conditions, for use in residential 
dehumidifiers;
     Listing HFC-32 as acceptable, subject to use conditions, 
for use in self-contained room ACs and heat pumps (HPs);
     Listing R-1150 as acceptable, subject to use conditions 
and narrowed use limits, for use in very low temperature refrigeration 
(VLTR);
     Listing 2-bromo-3,3,3-trifluoropropene (2-BTP) as 
acceptable, subject to use conditions, in streaming--for non-
residential use, except home offices and boats--and total flooding--in 
normally unoccupied spaces under 500 ft\3\;
     Listing EXXFIRE[supreg] as acceptable, subject to use 
conditions, in total flooding--for normally unoccupied areas; and
     Listing Powdered Aerosol H, also known as Pyroquench-
[alpha]TM, as acceptable, subject to use conditions, in 
total flooding--for normally unoccupied areas.
    EPA is finalizing these new listings after its evaluation of human 
health and environmental information for these substitutes in the 
refrigeration and AC sector and the fire suppression sector under the 
Significant New Alternatives Policy (SNAP) program based on the 
information that EPA has included in the docket. This action provides 
additional flexibility for industry by providing new options in 
specific uses.
SNAP Program Background
    The SNAP program implements section 612 of the Clean Air Act (CAA). 
Several major provisions of section 612 are:
1. Rulemaking
    Section 612(c) requires EPA to promulgate rules making it unlawful 
to replace any class I (chlorofluorocarbon (CFC), halon, carbon 
tetrachloride, methyl chloroform, methyl bromide, 
hydrobromofluorocarbon, and chlorobromomethane) or class II 
(hydrochlorofluorocarbon (HCFC)) ozone depleting substance (ODS) with 
any substitute that the Administrator determines may present adverse 
effects to human health or the environment where the Administrator has 
identified an alternative that (1) reduces the overall risk to human 
health and the environment and (2) is currently or potentially 
available.
2. Listing of Unacceptable/Acceptable Substitutes
    Section 612(c) requires EPA to publish a list of the substitutes 
that it finds to be unacceptable for specific uses and to publish a 
corresponding list of acceptable substitutes for specific uses.
3. Petition Process
    Section 612(d) grants the right to any person to petition EPA to 
add a substance to, or delete a substance from, the lists published in 
accordance with section 612(c).
4. 90-Day Notification
    Section 612(e) directs EPA to require any person who produces a 
chemical substitute for a class I substance to notify the Agency not 
less than 90 days before a new or existing chemical is introduced into 
interstate commerce for significant new use as a substitute for a class 
I substance. The producer must also provide the Agency with the 
producer's unpublished health and safety studies on such substitutes.
    The regulations for the SNAP program are promulgated at 40 Code of 
Federal Regulations (CFR) part 82, subpart G, and the Agency's process 
for reviewing SNAP submissions is described in regulations at 40 CFR 
82.180. Under these rules, the Agency has identified five types of 
listing decisions: acceptable; acceptable, subject to use conditions; 
acceptable, subject to narrowed use limits; unacceptable; and pending 
(40 CFR 82.180(b)). Use conditions and narrowed use limits are both 
considered ``use restrictions,'' as described below. Substitutes that 
are deemed acceptable with no use restrictions (no use conditions or 
narrowed use limits) can be used for all applications within the 
relevant end-uses in the sector. After reviewing a substitute, the 
Agency may determine that a substitute is acceptable only if certain 
conditions in the way that the substitute is used are met, to minimize 
risks to human health and the environment. EPA describes such 
substitutes as ``acceptable, subject to use conditions'' (40 CFR 
82.180(b)(2)). For some substitutes, the Agency may

[[Page 26384]]

permit a narrowed range of use within an end-use or sector. For 
example, the Agency may limit the use of a substitute to certain end-
uses or specific applications within an industry sector. EPA describes 
these substitutes as ``acceptable, subject to narrowed use limits.'' 
Under the narrowed use limit, users intending to adopt these 
substitutes ``must ascertain that other alternatives are not 
technically feasible.'' (40 CFR 82.180(b)(3)).
    In making decisions regarding whether a substitute is acceptable or 
unacceptable, and whether substitutes present risks that are lower than 
or comparable to risks from other substitutes that are currently or 
potentially available in the end-uses under consideration, EPA examines 
the criteria in 40 CFR 82.180(a)(7)(i) through (vii):

    ``(i) Atmospheric effects and related health and environmental 
impacts; (ii) General population risks from ambient exposure to 
compounds with direct toxicity and to increased ground-level ozone; 
(iii) Ecosystem risks; (iv) Occupational risks; (v) Consumer risks; 
(vi) Flammability; and (vii) Cost and availability of the 
substitute.''.

    Many SNAP listings include ``comments'' or ``further information'' 
to provide additional information on substitutes. Since this additional 
information is not part of the regulatory decision under SNAP, these 
statements are not binding for use of the substitute under the SNAP 
program. However, regulatory requirements so listed are binding under 
other regulatory programs (e.g., worker protection regulations 
promulgated by the U.S. Occupational Safety and Health Administration 
(OSHA)). The ``further information'' classification does not 
necessarily include all other legal obligations pertaining to the use 
of the substitute. While the items listed are not legally binding under 
the SNAP program, EPA encourages users of substitutes to apply all 
statements in the ``Further Information'' column in their use of these 
substitutes. In many instances, the information simply refers to sound 
operating practices that have already been identified in existing 
industry and/or building codes or standards. Thus, many of the 
statements, if adopted, would not require the affected user to make 
significant changes in existing operating practices.
    For additional information on the SNAP program, visit the SNAP 
website at https://www.epa.gov/snap. The full lists of acceptable 
substitutes for ODS in all industrial sectors are available at https://www.epa.gov/snap/snap-substitutes-sector. For more information on the 
Agency's process for administering the SNAP program or criteria for 
evaluation of substitutes, refer to the initial SNAP rulemaking 
published March 18, 1994 (59 FR 13044), codified at 40 CFR part 82, 
subpart G. SNAP decisions and the appropriate Federal Register 
citations can be found at: https://www.epa.gov/snap/snap-regulations. 
Substitutes listed as unacceptable; acceptable, subject to narrowed use 
limits; or acceptable, subject to use conditions, are also listed in 
the appendices to 40 CFR part 82, subpart G.

B. Does this action apply to me?

    The following list identifies regulated entities that may be 
affected by this rule and their respective North American Industrial 
Classification System (NAICS) codes:

 Plumbing, Heating, and Air Conditioning Contractors (NAICS 
238220)
 All Other Basic Organic Chemical Manufacturing (NAICS 325199)
 Pharmaceutical Preparations (e.g., Capsules, Liniments, 
Ointments, Tablets) Manufacturing (NAICS 325412)
 Air Conditioning and Warm Air Heating Equipment and Commercial 
and Industrial Refrigeration Equipment Manufacturing (NAICS 333415)
 Household Appliances, Electric Housewares, and Consumer 
Electronics Merchant Wholesalers (NAICS 423620)
 Refrigeration Equipment and Supplies Merchant Wholesalers 
(NAICS 423740)
 Recyclable Material Merchant Wholesalers (NAICS 423930)
 Appliance Repair and Maintenance (NAICS 811412)
 Fire Protection (NAICS 922160)

    This list is not intended to be exhaustive, but rather to provide a 
guide for readers regarding entities likely to be affected by this 
action. To determine whether your facility, company, business, or 
organization could be affected by this action, you should carefully 
examine the regulations at 40 CFR part 82, subpart G and the revisions 
below. If you have questions regarding the applicability of this action 
to a particular entity, consult the person listed in the FOR FURTHER 
INFORMATION CONTACT section.

C. What acronyms and abbreviations are used in the preamble?

    Below is a list of acronyms and abbreviations used in the preamble 
of this document:

2-BTP--2-bromo-3,3,3-trifluoropropene
AC--Air Conditioning or Air Conditioner
ACGIH--American Conference of Governmental Industrial Hygienists
AEL--Acceptable Exposure Limit
AHAM--Association of Home Appliance Manufacturers
AHRI--Air-Conditioning, Heating, and Refrigeration Institute
AIHA--American Industrial Hygiene Association AIM Act--American 
Innovation and Manufacturing Act of 2020
ANSI--American National Standards Institute
ASHRAE--American Society of Heating, Refrigerating and Air-
Conditioning Engineers
ASTM--American Society for Testing and Materials
CAA--Clean Air Act
CAS Reg. No.--Chemical Abstracts Service Registry Identification 
Number
CBI--Confidential Business Information
CFC--Chlorofluorocarbon
CFR--Code of Federal Regulations
CRA--Congressional Review Act
CO2--Carbon Dioxide
EEAP--Environmental Effects Assessment Panel
EIA--Environmental Investigation Agency
EPA--United States Environmental Protection Agency
FR--Federal Register
GWP--Global Warming Potential
HCFC--Hydrochlorofluorocarbon
HCFO--Hydrochlorofluoroolefin
HFC--Hydrofluorocarbon
HFO--Hydrofluoroolefin
HP--Heat Pump
ICF--ICF International, Inc.
IEC--International Electrotechnical Commission
IPAC--Industrial Process Air Conditioning
IPCC--Intergovernmental Panel on Climate Change
LFL--Lower Flammability Limit
LOAEL--Lowest Observed Adverse Effect Level
MIAQ--Madison Indoor Air Quality
MVAC--Motor Vehicle Air Conditioning
NAAQS--National Ambient Air Quality Standards
NAICS--North American Industrial Classification System
NARA--National Archives and Records Administration
NFPA--National Fire Protection Association
NIOSH--National Institute for Occupational Safety and Health
NPRM--Notice of Proposed Rulemaking
NRTL--Nationally Recognized Testing Laboratories
ODP--Ozone Depletion Potential
ODS--Ozone Depleting Substances
OMB--United States Office of Management and Budget
OSHA--United States Occupational Safety and Health Administration
PFAS--Per- and poly-fluoroalkyl substances
PFCs--Perfluorocarbons
PMS--Pantone[supreg] Matching System
ppm--Parts Per Million
PRA--Paperwork Reduction Act
PTAC--Packaged Terminal Air Conditioner
PTHP--Packaged Terminal Heat Pump
RAL--``Reichs-Ausschu[szlig] f[uuml]r Lieferbedingungen und 
G[uuml]tesicherung,''

[[Page 26385]]

Germany's National Commission for Delivery Terms and Quality 
Assurance
RCRA--Resource Conservation and Recovery Act
RFA--Regulatory Flexibility Act
SCBA--Self-Contained Breathing Apparatus
SDS--Safety Data Sheet
SIP--State Implementation Plan
SNAP--Significant New Alternatives Policy
TFA--trifluoroacetic acid
TLV-TWA--Threshold Limit Value-Time-Weighted Average
TSCA--Toxic Substances Control Act
TWA--Time Weighted Average
UL--UL, formerly known as Underwriters Laboratories, Inc.
UMRA--Unfunded Mandates Reform Act
VOC--Volatile Organic Compound, Volatile Organic Compounds
VLTR--Very Low Temperature Refrigeration
WCFF--Worst Case of Fractionation for Flammability
WCF--Worst Case of Formulation for Flammability
WEEL--Workplace Environmental Exposure Limit
WMO--World Meteorological Organization

II. What is EPA finalizing in this action?

    This section of the preamble describes EPA's final listings for 
certain refrigerants and fire suppressants in specific end-uses, 
including final use restrictions. In addition, this section provides 
responses to comments EPA received on the proposed listings during the 
public comment period for the proposed rule. One comment was received 
after the close of the comment period, to which no response from the 
Agency is required. The regulatory text for new listings is codified in 
appendix X of 40 CFR part 82, subpart G. The regulatory text for a 
revised listing is codified in appendix R of 40 CFR part 82, subpart G. 
The final regulatory text contains listing decisions for the end-uses 
discussed throughout this section below.

A. Chillers--Listing of HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and 
R-454C as Acceptable, Subject to Use Conditions, for Use in New Chiller 
Equipment Used in Comfort Cooling, Including Both Commercial AC and 
Industrial Process Air Conditioning (IPAC)

    EPA previously listed HFO-1234yf as acceptable, subject to use 
conditions, in motor vehicle AC, in light-duty vehicles (74 FR 53445; 
October 19, 2009), in heavy-duty pickup trucks and complete heavy-duty 
vans (81 FR 86778; December 1, 2016) and in nonroad vehicles and 
service fittings for small refrigerant cans (87 FR 26276; May 4, 2022). 
EPA previously listed HFC-32 as acceptable, subject to use conditions, 
as a substitute in residential and light commercial AC and HPs (80 FR 
19454; April 10, 2015) (86 FR 24444; May 6, 2021) and previously listed 
R-452B, R-454A, R-454B, and R-454C, (hereafter called ``the four 
refrigerant blends''), as acceptable, subject to use conditions, as 
substitutes in residential and light commercial AC and HPs (86 FR 
24444; May 6, 2021).\1\
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    \1\ In this final rule, we use the term ``air conditioner'' and 
``AC'' to cover equipment that cools air, heats air, or has the 
function to do both (typically referred to as a ``heat pump''). 
While such equipment might humidify or dehumidify the air, the term 
does not include equipment whose purpose is for latent cooling only 
(i.e., dehumidifiers), which are a separate end-use under SNAP and 
are addressed in section II.B of this final rule.
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    This final rulemaking finds HFC-32, HFO-1234yf, and the four 
refrigerant blends acceptable, subject to use conditions, as 
substitutes in chillers. The SNAP program divides chillers for comfort 
cooling into two general types based on the type of compressor used in 
the system, i.e., centrifugal and positive displacement compressors 
(including reciprocating, screw, scroll and rotary) chillers. EPA 
proposed to list HFO-1234yf, R-454A, R-454B, and R-454C as acceptable 
in all new chillers for comfort cooling and proposed to list HFC-32 and 
R-452B as acceptable only in new scroll and rotary chillers for comfort 
cooling. After consideration and evaluation of the comments received by 
the Agency in response to the July 28, 2022, notice of proposed 
rulemaking (87 FR 45508; hereafter, ``NPRM''), EPA is finalizing the 
listings for HFO-1234yf, R-454A, R-454B, and R-454C in chillers for 
comfort cooling as proposed. After consideration and evaluation of the 
comments received, EPA is broadening the listings for HFC-32 and R-452B 
relative to the NPRM, and is listing these alternatives as acceptable 
with use conditions across all chiller types for all comfort cooling 
applications, including but not limited to use in commercial AC and 
IPAC.
    Several use conditions finalized for chillers are identical to 
those finalized for other end-uses (residential dehumidifiers and 
residential and light commercial AC and HPs) finalized in sections II.B 
and II.D. below. Because of this similarity, EPA discusses the use 
conditions that would apply to all three end-uses in detail in section 
II.E below. For chillers, EPA is also finalizing an additional use 
condition related to adherence to the ASHRAE 15-2019 standard. In 
summary, the use conditions for chillers are:
    (1) New equipment only--These refrigerants may be used only in new 
equipment designed specifically and clearly identified for the 
refrigerant, i.e., none of these substitutes may be used as a 
conversion or ``retrofit'' refrigerant for existing equipment.
    (2) UL Standard--These refrigerants may be used only in chiller 
equipment that meet all requirements listed in the 3rd edition, dated 
November 1, 2019, of UL Standard 60335-2-40, ``Household and Similar 
Electrical Appliances--Safety--Part 2-40: Particular Requirements for 
Electrical Heat Pumps, Air Conditioners and Dehumidifiers.'' In cases 
where this final rule includes requirements different than those of the 
3rd edition of UL Standard 60335-2-40, the appliance would need to meet 
the requirements of this final rule in place of the requirements in UL 
60335-2-40, 3rd Edition. See section II.E below for further discussion 
on the requirements of this standard that EPA is incorporating by 
reference.
    (3) Warning labels--Several warning labels are required as use 
conditions as detailed in section II.E below. These labels are similar 
or verbatim in language to those required by UL 60335-2-40, 3rd 
Edition. The warning labels must be provided in letters no less than 
6.4 mm (\1/4\ inch) high and must be permanent.
    (4) Markings--Equipment must have distinguishing red 
(Pantone[supreg] Matching System (PMS) #185 or Reichs-Ausschu[szlig] 
f[uuml]r Lieferbedingungen und G[uuml]tesicherung \2\ (RAL) 3020) 
color-coded hoses and piping to indicate use of a flammable 
refrigerant. The chiller equipment shall have marked service ports, 
pipes, hoses and other devices through which the refrigerant is 
serviced. Markings shall extend at least 1 inch (25 mm) from the 
servicing port and shall be replaced if removed.
---------------------------------------------------------------------------

    \2\ Germany's National Commission for Delivery Terms and Quality 
Assurance.
---------------------------------------------------------------------------

    (5) For chillers, EPA is also finalizing a use condition related to 
adherence to the ASHRAE 15-2019 standard in addition to those common 
finalized use conditions for chillers, residential dehumidifiers, and 
self-contained room ACs. Specifically, EPA is requiring that these 
refrigerants may only be used in chillers that meet all requirements 
listed in the American National Standards Institute (ANSI)/ASHRAE 
Standard 15-2019 (hereafter ``ASHRAE 15-2019''). In cases where this 
final rule includes requirements different than those of ASHRAE 15-
2019,\3\ EPA is finalizing that the chiller appliance needs to meet the 
requirements of this final rule in place of the requirements in the 
ASHRAE Standard. This additional use

[[Page 26386]]

condition is discussed further in section II.A.4, below.
---------------------------------------------------------------------------

    \3\ ASHRAE, 2019b. American National Standards Institute (ANSI)/
American Society for Heating, Refrigerating, and Air-Conditioning 
Engineers (ASHRAE) Standard 15. Safety Standard for Refrigeration 
Systems. 2019.
---------------------------------------------------------------------------

    EPA notes that there may be other requirements pertaining to the 
manufacture, use, handling, and disposal of the listed refrigerants 
that are not included in the information listed in the tables (e.g., 
the CAA section 608(c)(2) venting prohibition \4\ or Department of 
Transportation requirements for transport of flammable gases). 
Flammable refrigerants being recovered or otherwise disposed of from 
chillers are likely to be hazardous waste under the Resource 
Conservation and Recovery Act (RCRA) (see 40 CFR parts 260-270).
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    \4\ Under section 608(c)(2) of the CAA and EPA's regulations at 
40 CFR 82.154(a)(1), it is unlawful for any person, in the course of 
maintaining, servicing, repairing, or disposing of an appliance or 
industrial process refrigeration, to knowingly vent or otherwise 
knowingly release or dispose of any substitute substance for a class 
I or class II substance used as a refrigerant in such appliance (or 
industrial process refrigeration) in a manner which permits such 
substance to enter the environment. As provided in 40 CFR 
82.154(a)(1), certain substitutes in certain end-uses have been 
exempted from this prohibition. References to the venting 
prohibition throughout this final rule refer to these provisions.
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1. Background on Chillers--Commercial AC and IPAC

    This rulemaking applies to chillers that are covered by the UL 
60335-2-40 standard ``Household and Similar Electrical Appliances--
Safety--Part 2-40: Requirements for Electrical Heat Pumps, Air 
Conditioners and Dehumidifiers'' and ASHRAE Standard 15-2019, ``Safety 
Standard for Refrigeration Systems.'' EPA understands that UL 60335-2-
40 covers chillers used for comfort cooling.
    In the initial rule establishing the SNAP program (59 FR 13044; 
March 18, 1994), EPA included within the refrigeration and AC sector 
the end-use ``commercial comfort air conditioning'' and then elaborated 
on that end-use by saying that ``CFCs are used in several different 
types of mechanical commercial comfort AC systems, known as chillers.'' 
EPA indicated ``that over time, existing cooling capacity [from 
chillers] will be either retrofitted or replaced by systems using non-
CFC refrigerants in a vapor compression cycle or by alternative 
technologies.'' EPA also explained in that rule that vapor compression 
chillers can be categorized by the type of compressor used, including 
centrifugal, rotary, screw, scroll and reciprocating compressors. These 
compressor types are also divided into centrifugal and positive 
displacement chillers, the latter of which includes those with 
reciprocating, screw, scroll or rotary compressors.
    Centrifugal chillers are equipment that utilize a centrifugal 
compressor in a vapor-compression refrigeration cycle. Centrifugal 
chillers are typically used for commercial comfort AC, although other 
uses, that we are not addressing here, do exist. Centrifugal chillers 
can be found in office buildings, hotels, arenas, convention halls, 
airport terminals and other buildings. Centrifugal chillers tend to be 
used in larger buildings.
    Positive displacement chillers are those that utilize positive 
displacement compressors such as reciprocating, screw, scroll or rotary 
types. Positive displacement chillers are applied in similar situations 
as centrifugal chillers, again primarily for commercial comfort AC, 
except that positive displacement chillers tend to be used for smaller 
capacity needs such as in mid- and low-rise buildings.
    A chiller is a type of equipment using refrigerant that typically 
cools water or a brine solution, which is then pumped to fan coil units 
or other air handlers to cool the air that is supplied to the occupied 
spaces transferring the heat to the water. The heat absorbed by the 
water can then be used for heating purposes, and/or can be transferred 
directly to the air (``air-cooled''), to a cooling tower or body of 
water (``water-cooled''), or through evaporative coolers 
(``evaporative-cooled''). A chiller or a group of chillers could 
similarly be used for district cooling where the chiller plant cools 
water or another fluid that is then pumped to multiple locations being 
served such as several different buildings within the same complex. 
Chillers may also be used to maintain operating temperatures in various 
types of buildings, for example, in data centers, server farms, and 
agricultural/food operations. Chillers are used in other applications, 
for example, to cool process streams in industrial applications. 
Chillers are also used for comfort cooling of operators or climate 
control and protecting process equipment in industrial buildings, for 
example, in industrial processes when ambient temperatures could 
approach 200 [deg]F (93 [deg]C) and corrosive conditions could exist. 
The listing finalized today applies to all types of chillers in comfort 
cooling applications.

2. What are the ASHRAE classifications for refrigerant flammability?

    The ANSI/ASHRAE Standard 34-2019 assigns a safety group 
classification for each refrigerant which consists of two to three 
alphanumeric characters (e.g., A2L or B1). The initial capital letter 
indicates the toxicity, and the numeral denotes the flammability. 
ASHRAE classifies Class A refrigerants as refrigerants for which 
toxicity has not been identified at concentrations less than or equal 
to 400 parts per million (ppm) by volume, based on data used to 
determine threshold limit value-time-weighted average (TLV-TWA) or 
consistent indices. Class B signifies refrigerants for which there is 
evidence of toxicity at concentrations below 400 ppm by volume, based 
on data used to determine TLV-TWA or consistent indices.
    The refrigerants are also assigned a flammability classification of 
1, 2, 2L, or 3. Tests for flammability are conducted in accordance with 
American Society for Testing and Materials (ASTM) E681 using a spark 
ignition source at 140 [deg]F (60 [deg]C) and 14.7 psia (101.3 kPa).\5\ 
The flammability classification ``1'' is given to refrigerants that, 
when tested, show no flame propagation. The flammability classification 
``2'' is given to refrigerants that, when tested, exhibit flame 
propagation, have a heat of combustion less than 19,000 kJ/kg (8,169 
Btu/lb), and have a lower flammability limit (LFL) greater than 0.10 
kg/m\3\. The flammability classification ``2L'' is given to 
refrigerants that, when tested, exhibit flame propagation, have a heat 
of combustion less than 19,000 kJ/kg (8,169 BTU/lb), have an LFL 
greater than 0.10 kg/m\3\, and have a maximum burning velocity of 10 
cm/s or lower when tested in dry air at 73.4 [deg]F (23.0 [deg]C) and 
14.7 psi (101.3 kPa). The flammability classification ``3'' is given to 
refrigerants that, when tested, exhibit flame propagation and that 
either have a heat of combustion of 19,000 kJ/kg (8,169 BTU/lb) or 
greater or have an LFL of 0.10 kg/m\3\ or lower.
---------------------------------------------------------------------------

    \5\ ASHRAE, 2019a. ANSI/ASHRAE Standard 34-2019: Designation and 
Safety Classification of Refrigerants.
---------------------------------------------------------------------------

    For flammability classifications, refrigerant blends are designated 
based on the worst case of formulation for flammability and the worst 
case of fractionation for flammability determined for the blend.

[[Page 26387]]

[GRAPHIC] [TIFF OMITTED] TR28AP23.000

    Using these safety group classifications, ANSI/ASHRAE Standard 34-
2019 categorizes HFO-1234yf, HFC-32 and the four refrigerant blends in 
this section of this final rule in the A2L Safety Group.
3. What are HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-454C and 
how do they compare to other refrigerants in the same end-use?
    HFO-1234yf and HFC-32 are lower flammability refrigerants, and the 
four refrigerant blends are lower flammability refrigerant blends, all 
with an ASHRAE safety classification of A2L. The respective Chemical 
Abstracts Service Registry Identification Numbers (CAS Reg. Nos.) of 
HFO-1234yf, HFC-32 and the components of the four refrigerant blends 
are listed below.
    HFO-1234yf, also known by the trade names ``Solstice[supreg] yf'' 
and ``OpteonTM YF,'' is also known as 2,3,3,3-
tetrafluoroprop-1-ene (CAS Reg. No. 754-12-1). HFC-32 is also known as 
R-32 or difluoromethane (CAS Reg. No. 75-10-5). R-452B, also known by 
the trade names ``OpteonTM XL 55'' and ``Solstice[supreg] 
L41y,'' is a blend consisting of 67 percent by weight HFC-32; seven 
percent HFC-125, also known as 1,1,1,2,2-pentafluoroethane (CAS Reg. 
No. 354-33-6); and 26 percent HFO-1234yf. R-454A, also known by the 
trade name ``OpteonTM XL 40,'' is a blend consisting of 35 
percent HFC-32 and 65 percent HFO-1234yf. R-454B, also known by the 
trade names ``OpteonTM XL 41'' and ``Puron 
AdvanceTM,'' is a blend consisting of 68.9 percent HFC-32 
and 31.1 percent HFO-1234yf. R-454C, also known by the trade name 
``OpteonTM XL 20,'' is a blend consisting of 21.5 percent 
HFC-32 and 78.5 percent HFO-1234yf.
    Redacted submissions and supporting documentation for HFO-1234yf, 
HFC-32, and the four refrigerant blends are provided in the docket for 
this final rule (EPA-HQ-OAR-2021-0836) at https://www.regulations.gov. 
EPA performed an assessment to examine the health and environmental 
risks of each of these substitutes. These assessments are available in 
the docket for this final rule.6 7 8 9 10 11 12
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    \6\ ICF, 2022a. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: R-
32.
    \7\ ICF, 2022b. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: 
HFO-123yf.
    \8\ ICF, 2022c. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: R-
452B.
    \9\ ICF, 2022d. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: R-
454A.
    \10\ ICF, 2022e. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: R-
454B.
    \11\ ICF, 2022f. Risk Screen on Substitutes in Chillers and 
Industrial Process Air Conditioning (New Equipment); Substitute: R-
454C.
    \12\ EPA notes that UL 60335-2-40 uses the Worst Case 
Formulation of Flammability (WCF) LFL, but that ASHRAE 34-2019 uses 
the Worst Case Fractionation of Flammability (WCFF) LFL for all of 
the blends except R-452B, in which case ASHRAE 34 references the WCF 
LFL. To be conservative, the Agency uses the WCFF LFL values for our 
flammability risk analysis. ASHRAE 34 plans to update their WCFF LFL 
values to WCF LFL values in future editions of the standard as a way 
to standardize LFLs going forward, after which the Agency may also 
consider switching to using WCF LFL values in the risk screens.
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    Environmental information: HFO-1234yf, HFC-32, and the four 
refrigerant blends have ODPs of zero.
    HFO-1234yf has a 100-year integrated GWP of less than 
four.13 14 15 HFC-32 has a GWP of 675. The four refrigerant 
blends are made up of the components HFC-32, HFC-125, and HFO-1234yf, 
which have GWPs of 675, 3,500, and less than four, respectively.\16\ If 
these values are weighted by mass percentage, then R-452B, R-454A, R-
454B, and R-454C have GWPs of about 700, 240, 470, and 150, 
respectively.
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    \13\ The GWP in World Meteorological Organization (2018) is 
listed as less than 1. Burkholder et al. Appendix A, Table A-1 in 
Scientific Assessment of Ozone Depletion: 2018, Global Ozone 
Research and Monitoring Project, Report No. 58, World Meteorological 
Organization, Geneva, Switzerland, http://ozone.unep.org/science/assessment/sap. (WMO, 2018)
    \14\ Nielsen et al., 2007. Nielsen, O.J., Javadi, M.S., Sulbaek 
Andersen, M.P., Hurley, M.D., Wallington, T.J., Singh, R. 2007. 
Atmospheric chemistry of CF3CF=CH2: Kinetics and mechanisms of gas-
phase reactions with Cl atoms, OH radicals, and O3. Chemical Physics 
Letters 439, 18-22. Available online at http://www.lexissecuritiesmosaic.com/gateway/FedReg/network_OJN_174_CF3CF=CH2.pdf.
    \15\ Hodnebrog [Oslash];. et al., 2013. Hodnebrog [Oslash];., 
Etminan, M., Fuglestvedt, J.S., Marston, G., Myhre, G., Nielsen, 
C.J., Shine, K.P., Wallington, T.J.: Global Warming Potentials and 
Radiative Efficiencies of Halocarbons and Related Compounds: A 
Comprehensive Review, Reviews of Geophysics, 51, 300-378, 
doi:10.1002/rog.20013, 2013
    \16\ Unless otherwise specified, GWP values are 100-year values 
from Intergovernmental Panel on Climate Change (IPCC) (2007) Climate 
Change 2007: The Physical Science Basis. Contribution of Working 
Group I to the Fourth Assessment Report of the Intergovernmental 
Panel on Climate Change. S. Solomon, D. Qin, M. Manning, Z. Chen, M. 
Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.). Cambridge 
University Press. Cambridge, United Kingdom 996 pp.
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    HFC-32, HFO-1234yf, and the other component of one of the four 
refrigerant blends, HFC-125, are excluded from EPA's regulatory 
definition of volatile organic compounds (VOC) (see 40 CFR 51.100(s)) 
for the purpose of addressing the development of State Implementation 
Plans (SIPs) to attain and maintain the National Ambient Air Quality 
Standards (NAAQS). The regulatory definition provides that ``any 
compound of carbon'' which ``participates in atmospheric

[[Page 26388]]

photochemical reactions'' is considered a VOC unless expressly excluded 
based on a determination of ``negligible photochemical reactivity.'' 
Under section 608(c)(2) of the CAA and EPA's regulations at 40 CFR 
82.154(a)(1), it is unlawful for any person, in the course of 
maintaining, servicing, repairing, or disposing of an appliance or 
industrial process refrigeration, to knowingly vent or otherwise 
knowingly release or dispose of any substitute substance for a class I 
or class II substance used as a refrigerant in such appliance (or 
industrial process refrigeration) in a manner which permits such 
substance to enter the environment.
    Flammability information: HFO-1234yf, HFC-32 and the four 
refrigerant blends are all classified as 2L under ASHRAE Standards 
reflecting that these compounds are flammable but have lower burning 
velocity than compounds listed as 2 or 3 under the ASHRAE standard.
    Toxicity and exposure data: HFO-1234yf, HFC-32 and the four 
refrigerant blends have an ASHRAE toxicity classification of A. 
Potential health effects of exposure to these substitutes include 
drowsiness or dizziness. The substitutes may also irritate the skin or 
eyes or cause frostbite. At sufficiently high concentrations, the 
substitutes may cause irregular heartbeat. The substitutes could cause 
asphyxiation if air is displaced by vapors in a confined space. These 
potential health effects are common to many refrigerants.
    The American Industrial Hygiene Association (AIHA) has established 
Workplace Environmental Exposure Limits (WEELs) of 1,000 ppm as an 
eight-hour time-weighted average (8-hr TWA) for HFC-32 and the 
component refrigerant HFC-125; the AIHA has established a WEEL of 500 
ppm as an 8-hr TWA for HFO-1234yf. The manufacturer of R-452B, R-454A, 
R-454B, and R-454C recommends Acceptable Exposure Limits (AELs) for the 
workplace, respectively, of 874, 690, 854, and 615 ppm on an 8-hr TWA 
for these blends. EPA anticipates that users will be able to meet the 
AIHA WEELs and manufacturers' AELs and address potential health risks 
by following requirements and recommendations in the manufacturers' 
safety data sheet (SDS), the final use conditions (including adherence 
to ASHRAE Standard 15), and other safety precautions common to the 
refrigeration and AC industry.17 18 19 20 21 22
---------------------------------------------------------------------------

    \17\ ICF, 2022a. Op. cit.
    \18\ ICF, 2022b. Op. cit.
    \19\ ICF, 2022c. Op. cit
    \20\ ICF, 2022d. Op. cit.
    \21\ ICF, 2022e. Op. cit.
    \22\ ICF, 2022e. Op. cit.
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: HFO-1234yf, HFC-
32, and the four refrigerant blends all have an ODP of zero, comparable 
to or lower than some of the acceptable substitutes in these end-uses, 
such as HFO-1234ze(E) with an ODP of zero. Although HCFC-123 and R-406A 
(with components HCFC-22 and HCFC-142b) have been listed acceptable in 
this end-use with ODPs of 0.02 and 0.057, respectively, HCFC-123 
(unless used, recovered, and recycled) may not be used as a refrigerant 
in equipment manufactured on or after January 1, 2020, under 40 CFR 
82.15(g)(5)(i).\23\ Similarly, components of R-406A (HCFC-22 and HCFC-
142b) (unless used, recovered, and recycled) may not be used as a 
refrigerant for use in chillers manufactured on or after January 1, 
2010, under 40 CFR 82.15(g)(2)(i).\24\ Under 40 CFR 82.16, EPA has not 
issued any production and consumption allowances for HCFC-22 and HCFC-
142b since 2019.
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    \23\ The regulations at 40 CFR 82.15(g)(5)(iii) provide a 
limited exception to the prohibition on use in 82.15(g)(5)(i), for 
use of HCFC-123 as a refrigerant in equipment manufactured on or 
after January 1, 2020 but before January 1, 2021 if the conditions 
of 40 CFR 82.15(g)(5)(iii) are met.
    \24\ The regulations at 40 CFR 82.15(g)(2)(ii) provide limited 
exceptions to the prohibitions in 82.15(g)(2)(i), including for 
HCFC-22 ``for use as a refrigerant in appliances manufactured before 
January 1, 2012, provided that the components are manufactured prior 
to January 1, 2010, and are specified in a building permit or a 
contract dated before January 1, 2010, for use on a particular 
project.''
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    HFC-32 and the four refrigerant blends' GWPs, ranging from about 
150 to 700, are higher than those of some of the acceptable substitutes 
for new centrifugal and positive displacement chillers, including HCFO-
1233zd(E), HFO-1336mzz(Z), and R-515B, with GWPs of 3.7, 9, and 287, 
respectively. The GWPs of HFO-1234yf, R-454A, R-454B, and R-454C are 
lower than some of the acceptable substitutes for new centrifugal and 
positive displacement chillers, such as R-450A and R-513A, with GWPs of 
approximately 600 and 630, respectively. HFC-32's and R-452B's GWPs of 
675 and about 700 are higher than the GWPs of those refrigerants. The 
GWPs of HFC-32 and R-452B are, however, lower than those of all the 
refrigerants that EPA listed as unacceptable for chillers as of January 
1, 2024, in the final rule issued December 1, 2016, which had GWPs of 
1,000 or higher. Further, HFC-32 and HFC-452B can be used in chillers 
that are designed to be used with refrigerants having higher pressure 
and higher volumetric capacity, unlike most of the other refrigerants 
listed acceptable in chillers (e.g., HCFO-1233zd(E), R-450A, and R-
513A). Volumetric capacity is important to achieve the cooling capacity 
needed without increasing equipment sizes, which could lead to weights 
exceeding code requirements, for instance, when a chiller on top of an 
existing building is replaced with a new one. Given the wide range of 
applications, not all refrigerants listed as acceptable under SNAP will 
be suitable for all equipment in the end-use. To provide additional 
options to ensure the availability of substitutes for the full range of 
chiller equipment for comfort cooling, EPA is finalizing the listings 
for HFC-32 and R-452B for all types of positive displacement chillers, 
as well as for centrifugal chillers and chillers for IPAC.
    HFC-32's and the four refrigerant blends' GWPs, ranging from about 
150 to 700, are higher than or comparable to those of some of the 
acceptable substitutes for new IPAC, including carbon dioxide 
(CO2), HFO-1336mzz(Z) and R-515B with GWPs of 1, 9 and 287 
respectively. Their GWPs are lower than some of the acceptable 
substitutes for new IPAC, such as HFC-134a, R-410A, and R-507A with 
GWPs of 1,430, 2,090 and 3,990 respectively. HFO-1234yf's GWP less than 
four is comparable to or lower than that of other acceptable 
substitutes for new IPAC, such as CO2, HFO-1336mzz(Z) and R-
515B with GWPs of 1, 9 and 287, respectively.
    Information regarding the toxicity of other available alternatives 
is provided in the listing decisions previously made (see https://www.epa.gov/snap/substitutes-chillers). Toxicity risks of use, 
determined by the likelihood of exceeding the exposure limit, of HFO-
1234yf, HFC-32, and the four refrigerant blends in these end-uses are 
evaluated in the risk screens referenced above. The toxicity risks of 
using HFO-1234yf, HFC-32, and the four refrigerant blends in chillers 
and IPAC are comparable to or lower than toxicity risks of other 
available substitutes in the same end-uses. Toxicity risks of the 
refrigerants can be minimized by use consistent with ASHRAE 15-2019--
which applies under the use conditions--and other industry standards, 
recommendations in the manufacturers' SDS, and other safety precautions 
common in the refrigeration and AC industry.
    The flammability risks with HFO-1234yf, HFC-32, and the four 
refrigerant blends in these end-uses, determined by the likelihood of 
exceeding their respective lower flammability limits, are evaluated in 
the risk screens referenced above. In conclusion, while these 
refrigerants may pose greater

[[Page 26389]]

flammability risk than other available substitutes in the same end-
uses, this risk can be minimized by use consistent with ASHRAE 15-
2019--which applies for certain charge sizes under the use conditions--
and other industry standards such as UL 60335-2-40--which also applies 
under the use conditions--as well as recommendations in the 
manufacturers' SDS and other safety precautions common in the 
refrigeration and AC industry. EPA is finalizing use conditions to 
reduce the potential risk associated with the flammability of these 
alternatives so that they will not pose significantly greater risk than 
other acceptable substitutes in this end-use.
4. Why is EPA finalizing these specific use conditions?
    The UL Standard 60335-2-40 discussed in section II.E indicates that 
refrigerant charges greater than a specific amount (called 
``m3'' in the UL Standard and based on the refrigerant's 
LFL) are beyond its scope and that national standards apply, such as 
ASHRAE 15-2019. Given that depending on the charge size of the 
equipment, either UL 60335-2-40 or ASHRAE 15-2019 would apply, EPA is 
including adherence to both standards as use conditions for chillers.
    EPA is finalizing that chillers using HFO-1234yf, HFC-32, or one of 
the four refrigerant blends must adhere to ASHRAE Standard 15-2019, 
with all addenda published by the date of the NPRM for this rule, 
including addenda a, b, c, d, e, f, i, j, k, m, n, o, q, and r. Where 
the requirements specified in this final rule and ASHRAE Standard 15 
are different, the requirements of this final rule would apply.
    A summary of relevant aspects of ASHRAE 15-2019 is provided here 
for information only. This is not meant to be a full explanation of the 
Standard or how it is applied. ASHRAE 15-2019 specifies requirements 
for refrigeration systems,\25\ including chillers, based on the safety 
group classification of the refrigerant used, the type of occupancy in 
the location for which the system is used, and whether refrigerant-
containing parts of the system enter the space or ductwork and so 
leakage in the space is deemed ``probable.'' ``High-Probability'' 
installations are those such that leaks or failures will result in 
refrigerant entering the occupied space. As explained above, HFO-
1234yf, HFC-32 and the four refrigerant blends are all classified as 
A2L refrigerants. Occupancies are divided into six classifications: 
institutional, public assembly, residential, commercial, large 
mercantile, and industrial. Examples of these include jails, theaters, 
apartment buildings, office buildings, shopping malls, and chemical 
plants, respectively.
---------------------------------------------------------------------------

    \25\ We note that while the ASHRAE 15-2019 purpose indicates 
``refrigeration systems,'' EPA believes this includes applications 
that are typically called ``air conditioning.''
---------------------------------------------------------------------------

    Sections 7.2 and 7.3 of ASHRAE Standard 15 determine the maximum 
amount of refrigerant allowed in the system, while section 7.4 provides 
an option to locate equipment outdoors or in a machinery room 
constructed and maintained under conditions specified in the standard. 
Section 7.6 of ASHRAE Standard 15 addresses the refrigerants in this 
proposal when used for human comfort in ``high-probability'' systems, 
including requirements for nameplates, labels, refrigerant detectors 
(under certain conditions), airflow initiation and other actions (if a 
rise in refrigerant concentration is detected), and other restrictions.
    In the interest of providing these ODS alternatives to industry 
quickly, as requested by commenters, and achieving reductions in other, 
less safe alternatives sooner, the Agency is finalizing use conditions 
that incorporate by reference the ASHRAE 15-2019 edition, as proposed, 
rather than a more recent version. EPA recognizes that ASHRAE 15 was 
recently updated and republished in late 2022. This final rule 
incorporates by reference all addenda published by the date of the 
NPRM, as proposed. EPA intends to review the 2022 version of ASHRAE 
Standard 15 and consider proposing revisions to the use conditions to 
incorporate by reference the 2022 version of that standard in a future 
notice and comment rulemaking.
    EPA is finalizing the use conditions to ensure safe use of these 
ODS alternatives regarding their flammability, toxicity, exposure, and 
environmental effects. As discussed below, commenters generally 
supported the use conditions. The use conditions identified in this 
section above are explained below, in section II.E.1, in greater 
detail.
5. What additional information is EPA including in these final 
listings?
    EPA is providing additional information related to these final 
listings. Since this additional information is not part of the 
regulatory decision under SNAP, these statements are not binding for 
use of the substitute under the SNAP program. See section II.E.2 below 
for further discussion on what additional information EPA is including 
in these final listings. While the items listed are not legally binding 
under the SNAP program, EPA encourages users of substitutes to apply 
all statements in the ``Further Information'' column in their use of 
these substitutes as best practices for safer use.
6. How is EPA responding to comments on chillers?
    Comment: Carrier commented expressing their support of listing HFO-
1234yf, HFC-32, R-452B, R-454A, R-454B, and R-454C as acceptable in 
chillers. Daikin described their support for listing HFC-32 and R-452B 
as acceptable in positive displacement chillers. Daikin agreed with 
``EPA's analysis of its application, and strongly supported the 
Agency's proposal to approve R-32 under the SNAP program for the end 
uses of new rotary and scroll comfort cooling and industrial process 
air conditioning chillers.'' Daikin voiced strong support and 
encouraged EPA to approve HFC-32 quickly.
    Response: EPA thanks Carrier and Daikin for their support of these 
listings in the chillers end-use. In this final rule, EPA is listing 
HFO-1234yf, R-454A, R-454B, R-454C, HFC-32, and R-452B in all 
centrifugal and positive displacement chillers for comfort cooling, 
including both commercial AC and IPAC.
    Comment: The Air-Conditioning, Heating, and Refrigeration Institute 
(AHRI), Carrier, Multistack, and Chemours all commented that EPA should 
not segment the chillers end-uses further by compressor type. Carrier 
stated that such segmentation leads to unnecessary complexity, while 
Multistack said it was likely to produce confusion regarding the 
application of products. Chemours commented that segmentation by 
compressor type may stifle innovation and create additional challenges 
for equipment manufacturers and end users working to adopt lower-GWP 
refrigerants. Chemours further stated that compressor type 
differentiation should only occur when necessary, because of technology 
limitations. Chemours also recommended that EPA remove references to 
chillers for industrial process refrigeration (IPR) to avoid confusion, 
as well as not distinguishing IPR equipment by compressor type.
    Response: EPA acknowledges the concerns commenters expressed 
regarding segmenting the current chillers end-uses by compressor types 
for the proposed listings of HFC-32 and R-452B in scroll and rotary 
chillers. After consideration of the comments received, in particular, 
the concerns for innovation and unnecessary complexity

[[Page 26390]]

as summarized above, EPA agrees that such segmentation is not necessary 
and could hinder the technical transition to lower-GWP refrigerants. 
Moreover, EPA does not view segmentation in this instance as providing 
any additional environmental benefit. Given EPA's understanding of the 
comments and the SNAP program's historical precedent of grouping 
together all positive displacement chillers despite their varying 
compressor types, EPA is finalizing the listings for HFC-32 and R-452B 
for all chillers rather than breaking out the listings by compressor 
type for scroll and rotary chillers.
    In response to Chemours's comment referencing IPR for chillers, EPA 
acknowledges the complexities associated with breaking out IPR by 
compressor type, similarly to chillers. EPA understands the standard UL 
60335-2-40 to apply only to comfort cooling and not to process cooling 
such as occurs in IPR. EPA may address additional substitutes for use 
in IPR in future rulemakings. The reference to chillers used for IPR 
remains in the preamble for this final rule to clarify that IPR is not 
in the scope of listings in this rule.
    Comment: Daikin commented on EPA's statement that ``EPA understands 
that the UL standard [60335-2-40] applies to chillers used for comfort 
cooling.'' Daikin went on to say ``that neither the scope statement nor 
the body of this UL standard make any such restriction as to the 
purpose of the heat pump, air-conditioner, or dehumidifier. Products 
evaluated to this UL standard are not limited to applications for human 
comfort and may also be applied to cool or heat various products or 
processes.'' They suggested that if EPA has safety concerns for IPAC, 
the Agency should include an ambient operating temperature limit of 140 
[deg]F. Daikin addressed the suitability of HFC-32 in IPAC and IPR, 
noting that ``EPA states in the preamble (87 FR 45514) that `HFC-32's . 
. . GWP [is] higher than those of some of the acceptable substitutes 
for new industrial process AC . . .', implying that HFC-32 is not 
suitable for industrial process refrigeration. Regardless of whether 
Daikin's SNAP information notice requested SNAP approval of HFC-32 in 
the industrial process refrigeration application, HFC-32 is also 
suitable for that application.''
    Response: EPA acknowledges Daikin's concerns about the scope of UL 
60335-2-40. Determining the coverage of UL standards to applications 
not covered in this rule is outside the scope of this rulemaking. 
However, for informational purposes in response to Daikin's comment, 
the Agency is providing some additional information regarding UL 60335-
2-40. As described in NOTE 104 in UL 60335-2-40, ``This standard does 
not apply to. . .
     appliances designed exclusively for industrial processing;
     appliances intended to be used in locations where special 
conditions prevail, such as the presence of a corrosive or explosive 
atmosphere (dust, vapour or gas).''
    Based on EPA's review of standard UL 60335-2-40 and conversations 
with UL, it is EPA's understanding that equipment for industrial 
processing, included in the bullet points above, is not covered by this 
standard, and instead is covered by UL 60335-2-89. Excluding equipment 
designed solely for industrial processes limits the scope of UL 60335-
2-40 to chillers designed for commercial and industrial comfort 
cooling. If a chiller in an industrial application is used mostly for 
comfort cooling and also cools processes or industrial equipment, EPA 
would consider it to fall under the SNAP end-use IPAC rather than IPR. 
The listings for HFC-32, described in this section above, will apply to 
these types of chillers on and after the effective date of this rule.
    The discussion of ambient operating temperature for IPAC equipment 
was included as part of the description of the end-use under SNAP, 
providing an example of possible operating conditions. Any safety 
concerns surrounding use of HFC-32 in this end-use are sufficiently 
addressed by the use conditions that apply as described in section 
II.E.1, below. EPA agrees with Daikin that HFC-32 is suitable for use 
in IPAC, given that the Agency proposed to list HFC-32 as acceptable in 
this end-use in SNAP NPRM 25 and is finalizing this listing in this 
rulemaking.
    Under SNAP, IPAC is considered comfort cooling equipment, as it 
protects the operators in addition to process equipment. EPA's SNAP 
program considers IPR equipment to be primarily for cooling of a 
process or product, not primarily for comfort cooling. EPA has not 
addressed or implied the suitability of HFC-32 for IPR in the NPRM or 
in this final rule. Any comments on the suitability of HFC-32 in IPR 
are outside the scope of the rulemaking. EPA is finalizing the listings 
for HFC-32 in chillers used in comfort cooling for commercial and 
industrial uses as described in this section of the preamble above.
    Comment: AHRI and Chemours noted that some of EPA's risk screens 
use the Worst Case of Fractionation for Flammability (WCFF) LFL values 
for the refrigerant blends rather than the Worst Case of Formulation 
for Flammability (WCF) when determining the lower flammability limit 
and requested that EPA uses the WCF LFL values for purposes of 
refrigerant risk analysis. Both commenters noted that UL 60335-2-40 
uses the WCF LFL, but that ASHRAE 34-2019 uses the WCFF LFL for all of 
the blends, except R-452B, in which case both ASHRAE 34 and EPA 
reference the WCF LFL. The commenters stated that ASHRAE 34 plans to 
update their WCFF LFL values to WCF LFL values in future editions of 
the standard as a way to standardize LFLs going forward.
    Response: EPA thanks the commenters for this information regarding 
WCFF and WCF LFL values. The Agency has added a footnote to this 
preamble acknowledging that this transition from using WCFF values to 
WCF values is taking place. EPA will consider updating risk screens for 
R-454A, R-454B, and R-454C in future rulemakings with more recent 
versions of the ASHRAE standards, using the WCF LFL values. Given the 
more conservative nature of WCFF LFL values over WCF LFL values, such 
an update to the risk screens' flammability analysis would result in a 
less conversative model. The determination of whether the LFL would be 
exceeded in a catastrophic refrigerant release scenario may change if 
using the WCF LFL values, possibly showing no flammability risk where 
there may have been flammability risk previously.
    Comment: Several citizens commented, acknowledging the safety of 
using A2L refrigerants in terms of their flammability and risk to the 
environment, especially relative to other alternatives available. These 
commenters stated that EPA should proceed with listing these 
refrigerants as acceptable.
    Response: EPA thanks the commenters for their support of listing 
the A2L refrigerants--HFO-1234yf and the refrigerants blends--as 
acceptable. EPA agrees that these refrigerants pose lower overall risk 
to human health and the environment, and thus we conclude it is 
appropriate to move forward with finalizing the listings for these 
refrigerants as described in the preamble above.

B. Residential Dehumidifiers--Listing of HFO-1234yf, HFC-32, R-452B, R-
454A, R-454B, and R-454C as Acceptable, Subject to Use Conditions, for 
Use in New Residential Dehumidifiers

    EPA previously listed HFO-1234yf as acceptable, subject to use 
conditions in

[[Page 26391]]

motor vehicle AC in light-duty vehicles (74 FR 53445; October 19, 
2009), in heavy-duty pickup trucks and complete heavy-duty vans (81 FR 
86778; December 1, 2016) and in nonroad vehicles and service fittings 
for small refrigerant cans (87 FR 26276; May 4, 2022). EPA previously 
listed HFC-32 as acceptable, subject to use conditions, as a substitute 
in residential and light commercial AC and HPs (80 FR 19454; April 10, 
2015 and 86 FR 24444, May 6, 2021) and previously listed R-452B, R-
454A, R-454B, and R-454C (hereafter called ``the four refrigerant 
blends'') as acceptable, subject to use conditions, as substitutes in 
residential and light commercial AC and HPs (86 FR 24444; May 6, 2021).
    This final rulemaking finds HFC-32, HFO-1234yf, and the four 
refrigerant blends acceptable, subject to use conditions, as 
substitutes in residential dehumidifiers. After consideration and 
evaluation of the comments received by the Agency in response to the 
NPRM, EPA is finalizing the listings for HFC-32, HFO-1234yf, R-452B, R-
454A, R-454B, and R-454C in residential dehumidifiers as proposed.
    Several use conditions finalized for residential dehumidifiers are 
common to those for other end-uses in section II.A, above, and II.D, 
below. Because of this similarity, EPA discusses the use conditions 
that would apply to all three end-uses in section II.E. For residential 
dehumidifiers, those are the only use conditions EPA is finalizing and 
require the following:
    (1) New equipment only--These refrigerants may be used only in new 
equipment designed specifically and clearly identified for the 
refrigerant, i.e., none of these substitutes may be used as a 
conversion or ``retrofit'' refrigerant for existing equipment.
    (2) UL Standard--These refrigerants may be used only in residential 
dehumidifiers that meet all requirements listed in the 3rd edition, 
dated November 1, 2019, of UL Standard 60335-2-40, ``Household and 
Similar Electrical Appliances--Safety--Part 2-40: Particular 
Requirements for Electrical Heat Pumps, Air Conditioners and 
Dehumidifiers'' (UL Standard). In cases where this final rule includes 
requirements different from those of the 3rd edition of UL Standard 
60335-2-40, the appliance must meet the requirements of the final rule 
in place of the requirements in UL 60335-2-40, 3rd Edition. See section 
II.E below for further discussion on the requirements of this standard 
that EPA is incorporating by reference.
    (3) Warning labels--Several warning labels are required as use 
conditions as detailed in section II.E below. These labels are similar 
or verbatim in language to those required by the UL Standard. The 
warning labels must be provided in letters no less than 6.4 mm (\1/4\ 
inch) high and must be permanent.
    (4) Markings--Equipment must have distinguishing red (PMS #185 or 
RAL 3020) color-coded hoses and piping to indicate use of a flammable 
refrigerant. The residential dehumidifier shall have marked service 
ports, pipes, hoses and other devices through which the refrigerant is 
serviced. Markings shall extend at least 1 inch (25mm) from the 
servicing port and shall be replaced if removed.
    EPA notes that there may be other requirements pertaining to the 
manufacture, use, handling, and disposal of the refrigerants that are 
not included in the information listed in the tables (e.g., the CAA 
section 608(c)(2) venting prohibition or Department of Transportation 
requirements for transport of flammable gases). Flammable refrigerants 
being recovered or otherwise disposed of from residential dehumidifiers 
are likely to be hazardous waste under RCRA (see 40 CFR parts 260-270).
1. Background on Residential Dehumidifiers
    Residential dehumidifiers are primarily used to remove water vapor 
from ambient air or directly from indoor air for comfort or material 
preservation purposes in the context of the home.\26\ While AC systems 
often combine cooling and dehumidification, this end-use only serves 
the latter purpose and is often used in homes for comfort purposes. 
This equipment is self-contained and circulates air from a room, passes 
it through a cooling coil, and collects condensed water for disposal. 
Residential dehumidifiers fall under the scope of the UL 60335-2-40 
standard ``Household and Similar Electrical Appliances--Safety--Part 2-
40: Requirements for Electrical Heat Pumps, Air Conditioners and 
Dehumidifiers.''
---------------------------------------------------------------------------

    \26\ SNAP regulations (see 40 CFR 82.172) define residential use 
as use by a private individual of a chemical substance or any 
product containing the chemical substance in or around a permanent 
or temporary household, during recreation, or for any personal use 
or enjoyment. Use within a household for commercial or medical 
applications is not included in this definition, nor is use in 
automobiles, watercraft, or aircraft.
---------------------------------------------------------------------------

    Some dehumidifiers for residential or light commercial use are 
integrated with the space air conditioning equipment, for instance via 
a separate bypass in the duct through which air is dehumidified, a 
dehumidifying heat pipe across the indoor coil, or other types of 
energy recovery devices that move sensible and/or latent heat between 
air streams (e.g., between incoming air and air vented to the outside). 
EPA classifies this application as a component of a residential or 
light commercial AC system or HP. As such, EPA has already listed HFC-
32 as acceptable for such uses, subject to the use conditions specified 
in SNAP Rule 23 (86 FR 24444; May 6, 2021).
    This final rulemaking finds HFO-1234yf, HFC-32, and the four 
refrigerant blends acceptable, subject to use conditions, in self-
contained residential dehumidifiers. Note that dehumidifiers for 
residential or light commercial use that are integrated with AC 
equipment (i.e., not self-contained) are not addressed in this listing 
because EPA classifies that type of equipment as residential or light 
commercial AC and HPs.
2. What are the ASHRAE classifications for refrigerant flammability?
    HFO-1234yf and HFC-32 are lower flammability refrigerants, and the 
four refrigerant blends are lower flammability refrigerant blends, all 
with an ASHRAE safety classification of A2L. See section II.A.2 above 
for further discussion on ASHRAE classifications.
3. What are HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-454C and 
how do they compare to other refrigerants in the same end-use?
    See section II.A.3 above for further discussion on the 
environmental, flammability, toxicity, and exposure information for 
these refrigerants.

[[Page 26392]]

    Redacted submissions and supporting documentation for HFO-1234yf, 
HFC-32 and the four refrigerant blends are provided in the docket for 
this proposed rule (EPA-HQ-OAR-2021-0836) at https://www.regulations.gov. EPA performed an assessment to examine the health 
and environmental risks of each of these substitutes. These assessments 
are available in the docket for this final 
rule.27 28 29 30 31 32
---------------------------------------------------------------------------

    \27\ ICF, 2022g. Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: HFC-32.
    \28\ ICF, 2022h. Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: R-452B.
    \29\ ICF, 2022i Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: R-454A.
    \30\ ICF, 2022j. Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: R-454B.
    \31\ ICF, 2022k. Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: R-454C.
    \32\ ICF, 2022l. Risk Screen on Substitutes in Residential 
Dehumidifiers (New Equipment); Substitute: HFO-1234yf.
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: HFO-1234yf, HFC-
32, and the four refrigerant blends all have an ODP of zero, comparable 
to or lower than some of the acceptable substitutes in new residential 
dehumidifiers, such as HFC-134a, R-410A, and R-513A, with ODPs of zero. 
HCFC-22 and R-406A (a blend of HCFC-22 and HCFC-142b) have ODPs of 
0.055 and 0.057, respectively, and are listed as acceptable in new 
residential dehumidifiers. However, HCFC-22 and HCFC-142b are 
controlled substances under Title VI of the CAA and (unless used, 
recovered, and recycled) may not be used as a refrigerant in equipment 
manufactured on or after January 1, 2010, under 40 CFR 
82.15(g)(2)(i).\33\ Under 40 CFR 82.16, EPA has not issued any 
production and consumption allowances for HCFC-22 and HCFC-142b (which 
is a component of R-406A, along with HCFC-22) since 2019.
---------------------------------------------------------------------------

    \33\ The regulations at 40 CFR 82.15(g)(2)(ii) provide limited 
exceptions to the prohibitions in 82.15(g)(2)(i), including for 
HCFC-22 ``for use as a refrigerant in appliances manufactured before 
January 1, 2012, provided that the components are manufactured prior 
to January 1, 2010, and are specified in a building permit or a 
contract dated before January 1, 2010, for use on a particular 
project.''
---------------------------------------------------------------------------

    HFO-1234yf, R-454A, R-454B, and R-454C have GWPs ranging up to 
about 470, lower than all the acceptable substitutes for new 
residential dehumidifiers, including R-513A and R-410A with GWPs of 630 
and 2,090, respectively. HFC-32 and R-452B have GWPs of 675 and 700, 
respectively, which are lower than some of the other acceptable 
substitutes for new residential dehumidifiers, such as HFC-134a, R-
410A, and R-507A with GWPs of 1,430, 2,090 and 3,990 respectively, but 
higher than R-513A, with a GWP of about 630.
    Information regarding the toxicity of other available alternatives 
is provided in the previous listing decisions for new residential 
dehumidifiers (https://www.epa.gov/snap/substitutes-residential-dehumidifiers). Toxicity risks of use, determined by the likelihood of 
exceeding the exposure limit, of HFO-1234yf, HFC-32, and the four 
refrigerant blends in these end-uses are evaluated in the risk screens 
referenced above. The toxicity risks of using HFO-1234yf, HFC-32, and 
the four refrigerant blends in new residential dehumidifiers are 
comparable to or lower than toxicity risks of other available 
substitutes in the same end-use. Toxicity risks of the refrigerants can 
be mitigated by use consistent with ASHRAE 15 and other industry 
standards, recommendations in the manufacturers' SDS, and other safety 
precautions common in the refrigeration and AC industry.
    The flammability risk with HFO-1234yf, HFC-32, and the four 
refrigerant blends in the new residential dehumidifiers end-use, 
determined by the likelihood of exceeding their respective lower 
flammability limits, are evaluated in the risk screens referenced in 
this section above. While these refrigerants may pose greater 
flammability risk than other available substitutes in the new 
residential dehumidifiers end-use, this risk can be mitigated by use 
consistent with ASHRAE 15 and UL 60335-2-40--which are applicable under 
the use conditions--as well as recommendations in the manufacturers' 
SDS and other safety precautions common in the refrigeration and AC 
industry. EPA is finalizing use conditions to reduce the potential risk 
associated with the flammability of these alternatives so that they 
will not pose significantly greater risk than other acceptable 
substitutes in the new residential dehumidifiers end-use.
4. Why is EPA finalizing these specific use conditions?
    EPA is finalizing listing HFO-1234yf, HFC-32 and the four 
refrigerant blends as acceptable, subject to use conditions, for use in 
residential dehumidifiers for new equipment. EPA is finalizing the use 
conditions to ensure safe use of these ODS alternatives regarding their 
flammability, toxicity, exposure, and environmental effects. As 
discussed below, commenters generally supported the use conditions. The 
use conditions identified in this section above are explained below in 
section II.E.1 in greater detail.
5. What additional information is EPA including in these final 
listings?
    EPA is providing additional information related to these final 
listings. Since this additional information is not part of the 
regulatory decision under SNAP, these statements are not binding for 
use of the substitute under the SNAP program. See section II.E.2 below 
for further discussion on what additional information EPA is including 
in these final listings. While the items listed are not legally binding 
under the SNAP program, EPA encourages users of substitutes to apply 
all statements in the ``Further Information'' column in their use of 
these substitutes as best practices for safer use.
6. How is EPA responding to comments on residential dehumidifiers?
    Comment: Several commenters (AprilAire, the Association of Home 
Appliance Manufacturers (AHAM), Competition Advocates, GE Appliances/
Hair, and Madison Indoor Air Quality (MIAQ)) voiced general support for 
the proposed listing of HFC-32 as acceptable, subject to use 
conditions, in residential dehumidifiers. AHAM noted the industry is 
``already in the process of transitioning to lower GWP refrigerants for 
these products and prefers a national regulatory framework under which 
it can operate with a clear path to compliances.'' Competition 
Advocates commented on their SNAP application for HFC-32 in residential 
dehumidifiers and noted the importance of transitioning to lower-GWP 
alternatives. ``SNAP approval of R-32 use in residential dehumidifiers 
will allow the direct and indirect climate benefits of this lower GWP 
and more energy efficient refrigerant to be realized as consumers 
purchase and use these products.'' GE Appliances commented that they 
filed a SNAP application for the use of HFC-32 in residential 
dehumidifiers and noted support for SNAP Rule 25, urging EPA to move 
quickly in finalizing. MIAQ additionally expressed their support for 
listing R-454B as acceptable in the end-use.
    Response: EPA acknowledges these commenters' general support for 
the proposed listings for HFC-32 and R-454B in residential 
dehumidifiers, and appreciates the additional information provided by 
AHAM and Competition Advocates on the transition to lower-GWP 
refrigerants. EPA agrees with these comments and is aware that industry 
has already started this transition. After

[[Page 26393]]

considering all the public comments on this proposal, we are finalizing 
these listings as described in this section, II.B.
    Comment: AHRI, Carrier, Chemours, Desert-Aire, and MIAQ suggested 
that ``EPA may wish to incorporate residential and non-residential 
dehumidifiers into the currently used SNAP category of Residential and 
Light Commercial Air Conditioning and Heat Pumps,'' as all these 
products are developed together through UL 60335-2-40 (AHRI). MIAQ also 
recommended EPA ``revise and clarify the classification of different 
types of dehumidifiers to align with the definitions in the U.S. 
Department of Energy (DOE) test procedure at 10 Code of Federal 
Regulations (CFR) 430, Subpart B, Appendix X1 or in 10 CFR 430.2 and 
that the CFR definitions take precedence and may be modified by DOE.''
    Response: EPA thanks the commenters for their suggestions on how to 
classify dehumidification equipment. EPA is finalizing the listings for 
residential dehumidifiers as proposed. For a discussion on how EPA has 
decided to categorize dehumidification equipment, see the Agency's 
response to comment included in section II.C.2, below.

C. Non-Residential Dehumidifiers--Decision Not To Finalize the Proposed 
Listing of HFC-32 as Acceptable, Subject to Use Conditions, for Use in 
New Non-Residential Dehumidifiers

    After review of comments, EPA agrees that a new non-residential 
end-use is not necessary. Therefore, EPA is not finalizing the proposed 
listing of HFC-32 as acceptable, subject to use conditions for use in a 
new end-use for new non-residential dehumidifiers and instead is 
clarifying that SNAP considers dehumidifiers for non-residential use to 
fall under the residential and light commercial AC and HPs end-use. 
HFC-32 has previously been listed as acceptable for use in this end-
use.
1. Why is EPA not finalizing the proposal to list HFC-32 as acceptable, 
subject to use conditions, in new non-residential dehumidifiers?
    After review of the comments received relating to the creation of 
the non-residential end-use, EPA determined finalizing this section of 
the proposal is unnecessary. Commenters stated that before the NPRM, 
industry understood dehumidifiers in a commercial, or other non-
residential, context to be covered by the end-use residential and light 
commercial AC and HPs. If EPA were to finalize this new end-use, it 
would cause unnecessary confusion regarding which end-use certain 
dehumidification equipment would be covered by under the SNAP program. 
Given that dehumidifiers are covered by the same UL Standard as 
equipment included in residential and light commercial AC and HPs, and 
that charge sizes and room sizes are similar to light commercial AC 
systems, EPA considers the risk profile of non-residential 
dehumidifiers when using flammable refrigerants to be similar to that 
of other equipment in that end-use.\34\ Thus, in light of these 
comments and EPA's reflection on the current listings, standards, and 
the lack of any additional environmental protection provided by a 
separate listing for these dehumidifiers, EPA has determined that it is 
not necessary to list non-residential dehumidifiers as a separate end-
use. Instead, with today's action, EPA is clarifying that SNAP 
considers the equipment described in the non-residential dehumidifier 
section of the NPRM to be part of the SNAP end-use residential and 
light commercial AC and HPs, with alternatives listed acceptable 
previously in that end-use applying to dehumidifiers used in non-
residential settings.
---------------------------------------------------------------------------

    \34\ ICF, 2023a. Risk Screen on Substitutes in Residential and 
Light Commercial Air Conditioning and Heat Pumps (New Equipment); 
Substitute: HFC-32 (Difluoromethane).
---------------------------------------------------------------------------

2. How is EPA responding to comments on non-residential dehumidifiers?
    Comment: Anden, a manufacturer of agricultural dehumidifiers, 
commented in support of listing HFC-32 as acceptable in the non-
residential dehumidifiers end-use. In contrast, AHRI, Carrier, 
Chemours, Desert-Aire, and MIAQ submitted comments disagreeing with the 
proposed creation of a new non-residential dehumidifier end-use and the 
proposed listing of HFC-32 as the only refrigerant acceptable for this 
type of equipment.
    Chemours commented requesting EPA not to finalize creation of the 
new non-residential dehumidifiers end-use, given that industry has been 
classifying this type of equipment under residential and light 
commercial AC and HPs up until SNAP NPRM 25, and that the transition to 
lower-GWP options for non-residential dehumidifiers relies heavily on 
the availability of substitutes already listed acceptable in this end-
use. Chemours goes on to discuss how it would be a large burden on 
stakeholders to resubmit SNAP applications for all the alternatives 
listed in residential and light commercial AC and HPs, and disruption 
of the current manufacturing of OEMs who had been operating under the 
assumption that certain refrigerants were allowed for use in their non-
residential dehumidifier equipment that will no longer be acceptable if 
this end-use creation is finalized. MIAQ also suggested classifying 
non-residential dehumidifiers (or ``non-consumer dehumidifiers'') as 
part of the residential and light commercial AC and HPs end-use.
    AHRI and Desert-Aire commented suggesting EPA to include all 
dehumidifiers (both for residential and non-residential applications) 
into the existing residential and light commercial AC and HPs end-use, 
given that these equipment types are all covered under the same UL 
60335-2-40 standard.
    As mentioned above in section II.B, AHRI, Carrier, Chemours, 
Desert-Aire, and MIAQ suggested combining both the residential 
dehumidifiers and non-residential dehumidifiers end-uses into one end-
use, ``dehumidifiers.'' MIAQ commented recommending that EPA adopt 
DOE's definition of consumer product dehumidifiers, into the two 
subcategories of ``whole home'' and ``portable.'' MIAQ also suggested 
defining non-residential dehumidifiers as dehumidifiers that are not 
consumer products. Carrier, Chemours, Desert-Aire, and MIAQ also 
suggested that the five refrigerants being finalized in this rulemaking 
for residential dehumidifiers--HFO-1234yf, R-452B, R-454A, R-454B, and 
R-454C--should also be listed for non-residential dehumidifiers. 
Desert-Aire cited similarities in the use-cases of the end-uses as 
justification for including these refrigerants in both end-uses. MIAQ 
further suggested allowing all previous refrigerants listed as 
acceptable under residential dehumidifiers to be applied to all types 
of dehumidifiers. Chemours and MIAQ cited certain equipment that cannot 
clearly be placed into either residential and light commercial AC and 
HPs or non-residential dehumidifiers based on the definitions proposed 
by EPA, including dehumidifiers that are ducted into an HVAC system and 
can be run entirely independently of any AC.
    Response: EPA acknowledges the commenters' varied suggestions on 
the best path forward regarding dehumidification equipment 
classification. It is clear from EPA's review of the myriad comments 
received that the non-residential dehumidifier end-use as proposed is 
not necessary and that industry's understanding, previously to the 
proposed rule, was that non-residential dehumidifiers were part of the 
residential and light commercial AC and

[[Page 26394]]

HPs end-use. Moreover, if EPA had finalized this provision as proposed, 
it may have resulted in a review of other listed refrigerants to ensure 
that sufficient refrigerant options were available for this type of 
equipment. EPA agrees that by including non-residential dehumidifying 
equipment in an existing end-use, there will be sufficient refrigerant 
options available for this type of equipment. Thus, EPA has decided not 
to finalize the proposed creation of a new non-residential 
dehumidifiers end-use. Instead, EPA concludes that all dehumidifiers 
for use in non-residential settings are appropriately covered under the 
existing residential and light commercial AC and HPs end-use. Based on 
the action EPA is taking today, manufacturers of self-contained 
dehumidifiers for use in non-residential settings will be able to use 
HFC-32, as well as other substitutes that are listed as acceptable in 
the residential and light commercial AC and HPs end-use.
    EPA acknowledges the suggestion to combine all dehumidifiers, 
including the current residential dehumidifiers end-use, with the 
residential and light commercial AC and HPs end-use. These types of 
equipment are covered by the same safety standards and also have 
significant overlap in their risk profiles. EPA notes that the Agency 
has in the past separated residential dehumidifiers from residential 
AC, stating that ``While air conditioning systems often combine cooling 
and dehumidification, this application [residential dehumidifiers] 
serves only the latter purpose'' (March 18, 1994; 59 FR at 13071) and 
``. . . we use the term `air conditioner' and `AC' to cover equipment 
that cools air, heats air, or has the function to do both (typically 
referred to as a `heat pump'). While such equipment might humidify or 
dehumidify the air, the term does not include equipment whose purpose 
is for latent cooling only (i.e., dehumidifiers), which are a separate 
end-use under SNAP'' (June 12, 2020; 85 FR at 35880). EPA has not made 
comparable statements to separate commercial or industrial comfort 
cooling from commercial or industrial dehumidification, but neither has 
the Agency said before that these are in the same end-use. EPA may 
consider combining residential dehumidifiers with the residential and 
light commercial AC and HPs end-use in a future rulemaking, to give the 
public sufficient notice and opportunity to comment before potentially 
making such a change to the existing end-uses.
    Similarly, if EPA were to consider combining residential 
dehumidifiers with non-residential dehumidifiers, creating a general 
``dehumidifiers'' end-use, we would also take this action through 
notice-and-comment rulemaking. Although these equipment types are also 
similar, EPA believes that the ``light commercial'' aspect of the 
residential and light commercial AC and HPs end-use better covers the 
risk profile of non-residential dehumidifiers. These types of equipment 
are all covered by the UL 60335-2-40 safety standard and have 
significant overlap in their risk profiles because of similar room 
sizes and charge sizes required for self-contained ACs and HPs and 
dehumidifiers used in non-residential settings.
    Concerning the suggestion that EPA's SNAP program use DOE's 
definitions for dehumidifiers, EPA understands that consistency in 
equipment definitions between agencies is useful for stakeholders. 
However, EPA and DOE operate under separate authorities and in this 
context, these authorities have separate goals. Currently, the DOE's 
definitions of ``whole home'' versus ``portable'' dehumidifiers are 
similar to the SNAP definitions. EPA describes ``whole home'' 
dehumidifiers as ducted equipment, covered by the residential and light 
commercial AC and HPs end-use, while ``self-contained'' dehumidifiers, 
roughly equivalent to DOE's ``portable'' dehumidifiers, are covered by 
the residential dehumidifier end-use. DOE also defines equipment by 
user, describing equipment as either ``consumer'' or ``non-consumer'' 
products, whereas EPA's definitions reference whether or not the 
equipment is used in residential contexts. In this final rule, EPA is 
describing dehumidification equipment independently of DOE. However, 
EPA may consider taking action through a notice-and-comment rulemaking 
at a future date to adopt new definitions.
    While the suggestion to list the same six refrigerants proposed in 
the residential dehumidifiers end-use in the non-residential 
dehumidifiers end-use would provide more than HFC-32 as an option for 
the equipment, by including non-residential dehumidifiers in the 
residential and light commercial AC and HPs end-use, many more 
refrigerant options, beyond the six discussed, will be available.

D. Residential and Light Commercial AC and Heat Pumps (HPs)--Revision 
of Use Conditions Provided in the Previous Listing of HFC-32 as 
Acceptable for Use in New Self-Contained Room ACs and HPs

    EPA previously listed HFC-32 as acceptable, subject to use 
conditions, in new self-contained room ACs and HPs in SNAP Rule 19 (80 
FR 19461; April 10, 2015). In this action we are finalizing updates to 
applicable use conditions for new self-contained room ACs and HPs using 
HFC-32 to be consistent with the use conditions finalized in SNAP Rule 
23 (86 FR 24444; May 6, 2021). EPA proposed replacing the previously 
required use conditions in compliance with UL 484 Standard, 8th 
Edition, with updated use conditions in compliance with UL 60335-2-40 
Standard, 3rd Edition, effective 30 days after publication of the final 
rule. However, after review of the comments received, EPA has decided 
that manufacturers will be allowed to manufacture such equipment either 
according to UL 484, 8th Edition or according to UL 60335-2-40, 3rd 
Edition on or after the effective date of this final rule up to and 
including January 1st, 2024. Beginning January 2nd, 2024, UL will 
sunset UL 484 and only warning labels in compliance with UL 60335-2-40 
will be permitted. Equipment manufactured before the effective date of 
this final action in compliance with the SNAP requirements applicable 
at the time of manufacture will remain in compliance.
1. Background on Self-Contained Room ACs and HPs
    The residential and light commercial AC and HPs end-use includes 
equipment for cooling air in individual rooms, in single-family homes, 
and sometimes in small commercial buildings. This end-use differs from 
commercial comfort AC, which uses chillers that cool water that is then 
used to cool air throughout a large commercial building, such as an 
office building or hotel. Examples of equipment for residential and 
light commercial AC and HPs include:
     Central ACs, also called unitary AC or unitary split 
systems. These systems include an outdoor unit with a condenser and a 
compressor, refrigerant lines, an indoor unit with an evaporator, and 
ducts to carry cooled air throughout a building. Central heat pumps are 
similar but offer the choice to either heat or cool the indoor space. 
These systems are not addressed in this rule.\35\
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    \35\ EPA has received submissions for HFC-32 and the hydrocarbon 
blends R-441A and R-443A, and no other flammable refrigerants, in 
new unitary central air conditioners. This action does not address 
flammable refrigerants in unitary central air conditioners. 
Introduction into interstate commerce of refrigerants without giving 
timely and adequate notice to EPA is in violation of Section 612(e) 
of the CAA and the SNAP regulations at 40 CFR part 82, subpart G.
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     Multi-split ACs. These systems include one or more outdoor 
unit(s) with a condenser and a compressor and

[[Page 26395]]

multiple indoor units, each of which is connected to the outdoor unit 
by refrigerant lines. These systems are not addressed in this rule.
     Mini-split ACs. These systems include an outdoor unit with 
a condenser and a compressor and a single indoor unit that is connected 
to the outdoor unit by refrigerant lines. Cooled air exits directly 
from the indoor unit rather than being carried through ducts. These 
systems are not addressed in this rule.
     Window ACs. These are self-contained units that fit in a 
window with the condenser extending outside the window. These types of 
units are regulated under this rule.
     Packaged terminal ACs (PTACs) and packaged terminal HPs 
(PTHPs). These are self-contained units that consist of a separate, un-
encased combination of heating and cooling assemblies mounted through a 
wall.\36\ These types of units are regulated under this rule.
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    \36\ PTACs are intended for use in a single room, or potentially 
for two rooms next to each other, and use no external refrigerant 
lines. Typical applications include motel or dormitory air 
conditioners.
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     Portable room ACs. These are self-contained, factory-
sealed, single package units that are designed to be moved easily from 
room to room and are intended to provide supplemental cooling within a 
room. These units typically have wheels or casters for portability and, 
under the UL 484 Standard for room ACs, must have a fan which operates 
continuously when the unit is on. Portable room ACs may contain an 
exhaust hose that can be placed through a window or door to eject heat 
to the outside. These types of units are regulated under this rule.
    Of these types of equipment, window ACs, PTACs, PTHPs, and portable 
room ACs are self-contained equipment with the condenser, compressor, 
evaporator, and tubing all within casing in a single unit. These are 
the types of equipment for which EPA previously listed HFC-32 as 
acceptable, subject to use conditions, as codified in appendix R to 40 
CFR part 82, subpart G.
2. What are the ASHRAE classifications for refrigerant flammability?
    See section II.A.2 above for further discussion on ASHRAE 
classifications.
3. What is HFC-32 and how does it compare to other refrigerants in the 
same end-use?
    See section II.A.3 above for further discussion on the 
environmental, flammability, toxicity, and exposure information for 
HFC-32.
    Redacted submissions and supporting documentation for HFC-32 is 
provided in the docket for this proposed rule (EPA-HQ-OAR-2021-0836) at 
https://www.regulations.gov. EPA performed an assessment to examine the 
health and environmental risks of HFC-32. This assessment is available 
in the docket for this final rule.\37\
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    \37\ ICF, 2022n. Risk Screen on Substitutes in Residential and 
Light Commercial Air Conditioning and Heat Pumps (New Equipment); 
Substitute: HFC-32 (Difluoromethane).
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: HFC-32 has an ODP 
of zero, the same as other acceptable substitutes in this end-use, such 
as R-290, HFC-134a, R-410A, and R-513A, with ODPs of zero.
    HFC-32 has a GWP of 675, higher than some of the acceptable 
substitutes for residential and light commercial air conditioning and 
heat pumps, including ammonia absorption, R-290, and R-454B with GWPs 
of zero, three, and about 470, respectively. HFC-32's GWP is lower than 
some of the acceptable substitutes for residential and light commercial 
air conditioning and heat pumps, such as R-452B, HFC-134a, and R-410A, 
with GWPs of approximately 700, 1,430, and 2,090, respectively.
    Information on the toxicity and flammability risk of HFC-32 in this 
end-use category was provided in SNAP Rule 19. In summary, EPA found 
the toxicity risks of HFC-32 to be comparable to or lower than other 
acceptable alternatives. Although we noted that the flammability risk 
of HFC-32 may be greater than that of other available, nonflammable 
substitutes in the same end-use, we found that those risks are not 
significant even under worst-case assumptions. These risks of HFC-32 
are similar to the risks of other flammable refrigerants found 
acceptable for this end-use category in SNAP Rule 23 (i.e., R-452B, R-
454A, R-454B, R-454C, and R-457A). We noted there that this risk can be 
minimized by use consistent with industry standards such as UL 60335-2-
40--which would be required by our proposed revision to the use 
conditions--and other industry standards, such as ASHRAE 15, as well as 
recommendations in the manufacturers' SDS and other safety precautions 
common in the refrigeration and air conditioning industry. The updates 
to the use conditions proposed maintain the low potential risk 
associated with the flammability of this alternative so that it will 
not pose significantly greater risk than other acceptable substitutes 
in this end-use category.
4. What use conditions previously applied to this refrigerant in this 
end-use category?
    EPA previously found HFC-32 acceptable, subject to use conditions, 
in new residential and light commercial AC for self-contained room AC 
units, including PTAC units, PTHPs, window AC and HP units, and 
portable AC units, designed for use in a single room in SNAP Rule 19 
(80 FR 19454; April 10, 2015). Those requirements are codified in 
appendix R of 40 CFR part 82, subpart G. EPA provided information on 
the environmental and health properties of HFC-32 and the various 
substitutes available at that time for use in this end-use. 
Additionally, EPA's risk screen for this refrigerant is available in 
the docket for this previous rulemaking (EPA-HQ-OAR-2013-0748).
    HFC-32 has an ASHRAE classification of A2L, indicating that it has 
low toxicity and lower flammability. The flammability risks are of 
potential concern because residential ACs and HPs traditionally used 
refrigerants that are not flammable. In the presence of a higher energy 
ignition source (e.g., lighted match or a cigarette lighter), an 
explosion or a fire could occur if the concentration of HFC-32 were to 
exceed the LFL of 144,000 ppm by volume. In the preamble for the 
original listing for three flammable refrigerants, including HFC-32 and 
two A3 refrigerants, in self-contained ACs and HPs in SNAP Rule 19, EPA 
had described lower energy ignition sources (e.g., static electricity, 
a spark resulting from a closing door, or a cigarette) as possible 
ignition sources that were appropriate for the two A3 refrigerants, but 
not for HFC-32. This same description of ignition sources was used in 
the preamble of the July 2022 NPRM for this rule and it was not revised 
from the original listing in SNAP Rule 19 to only apply to HFC-32. 
After considering comments received on the proposal, in this preamble 
to the final rule, EPA is clarifying that A2Ls such as HFC-32 require 
greater energy input for ignition than previously described, and that a 
higher energy source, such as a lighted match, would be necessary.
    Previously, to address flammability, EPA listed HFC-32 as 
acceptable in new self-contained room AC units, subject to use 
conditions. The previous use conditions addressed safe use of this 
flammable refrigerant and included incorporation by reference of 
Supplement SA to the 8th edition (August 2, 2012) of UL Standard 484, 
refrigerant charge size limits based on cooling capacity and type of 
equipment, and requirements for markings and

[[Page 26396]]

warning labels on equipment using the refrigerant to inform consumers 
and technicians of potential flammability hazards. Without appropriate 
use conditions, the flammability risk posed by this refrigerant could 
be higher than non-flammable refrigerants because individuals may not 
be aware that their actions could potentially cause a fire, and because 
the refrigerant could be used in existing equipment that has not been 
designed specifically to minimize flammability risks. Our assessment 
and listing decisions in SNAP Rule 19 (80 FR 19454; April 10, 2015) 
found that with the use conditions, the overall risk of this 
substitute, including the risk due to flammability, does not present 
significantly greater risk in the end-use than other substitutes that 
are currently or potentially available for that same end-use.
5. What updates to the use conditions is EPA finalizing?
    EPA is finalizing the proposed updates to the use conditions that 
apply to HFC-32 in new self-contained room ACs and HPs for equipment 
manufactured after the effective date of this final rule, with the 
change from proposal that UL 484 may continue to be used up to and 
including its official sunset date, per UL, of January 1st, 2024. In 
the time between the effective date of this final rule and January 1st, 
2024, manufacturers will be allowed to follow either UL 484, 8th 
Edition or UL 60335-2-40, 3rd Edition. The period during which 
manufacturers may follow either standard provides sufficient time for 
manufacturers to transition from UL 484 to UL 60335-2-40. EPA is making 
this change after considering public comment on the timing for the 
adopting UL 60335-2-40, discussed further below in this section. 
Several of the updated use conditions finalized for self-contained room 
ACs and HPs are common to those finalized for other end-uses in 
sections II.A and II.B above. Because of this similarity, EPA discusses 
the use conditions that apply to all three end-uses in section II.E. 
For HFC-32 in self-contained room ACs and HPs, these are the use 
conditions EPA is finalizing. In summary, with the updates finalized, 
the use conditions are the following:
    (1) New equipment only--This refrigerant may only be used in new 
equipment designed specifically and clearly identified for the 
refrigerant, i.e., this substitute may not be used as a conversion or 
``retrofit'' refrigerant for existing equipment. This use condition is 
the same as what currently exists for HFC-32 in this end-use category.
    (2) UL Standard--This refrigerant (i.e., in this case, HFC-32) may 
be used only in equipment (i.e., in this case, self-contained room ACs 
and HPs) that meet all requirements listed either (a) in the 3rd 
edition, dated November 1, 2019, of UL Standard 60335-2-40, ``Household 
and Similar Electrical Appliances--Safety--Part 2-40: Particular 
Requirements for Electrical Heat Pumps, Air Conditioners and 
Dehumidifiers'' (UL Standard) or (b) in Supplement SA to the 8th 
edition, dated August 2nd, 2012, of UL 484, ``Room Air Conditioners.'' 
In cases where this final rule includes requirements different than 
those of the 3rd edition of UL Standard 60335-2-40 or of Appendix SA in 
the 8th edition of UL 484, EPA is requiring that the appliance would 
need to meet the requirements of this final rule in place of the 
requirements in the UL Standards. See section II.E below for further 
discussion on the requirements of the UL 60335-2-40 standard that EPA 
is incorporating by reference. This change in the use conditions allows 
the standard to which the equipment must adhere to be either Supplement 
SA to the 8th edition, dated August 2nd, 2012, of UL Standard 484, 
``Room Air Conditioners'' or the 3rd edition of UL 60335-2-40 until the 
UL 484 standard sunsets on January 1st, 2024. After that date, self-
contained room ACs and HPs must follow the 3rd edition of UL 60335-2-
40.\38\
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    \38\ EPA anticipates that we may propose to further update this 
use condition to more recent editions of the UL 60335-2-40 standard 
in a future rulemaking and may consider allowing more than one 
edition to be used during a specified time period.
---------------------------------------------------------------------------

    (3) Warning labels--Several warning labels were proposed as use 
conditions as detailed in section II.E below for equipment being 
designed in compliance with UL 60335-2-40. However, the previously 
required warning labels in compliance with UL 484 will also be 
acceptable through January 1st, 2024. Therefore, manufacturers will be 
allowed to manufacture such equipment either according to UL 484, 8th 
Edition or according to UL 60335-2-40, 3rd Edition on or after the 
effective date of this final rule up to and including January 1st, 
2024; after this date, UL will sunset UL 484 and only UL 60335-2-40 
will apply. Beginning January 2nd, 2024, only warning labels in 
compliance with UL 60335-2-40 will be permitted. Equipment manufactured 
before the effective date of this final action in compliance with the 
SNAP requirements applicable at the time of manufacture will remain in 
compliance. Equipment designed in compliance with either UL standard 
will be required to use warning label language that aligns with that 
standard using the font size specified by SNAP regulatory requirements. 
These labels are similar in language to those required by UL standards 
484, 8th Edition and 60335-2-40, 3rd Edition. The warning labels must 
be provided in letters no less than 6.4 mm (\1/4\ inch) high and must 
be permanent. While the font size is the same as in the use conditions 
that currently apply, several revisions to the labels and the language 
in them have changed for manufactures opting to adhere with the 3rd 
edition of UL 60335-2-40.
    (4) Markings--Equipment must have distinguishing red (PMS #185 or 
RAL 3020) color-coded hoses and piping to indicate use of a flammable 
refrigerant. The equipment shall have marked service ports, pipes, 
hoses, and other devices through which the refrigerant is serviced. 
Markings shall extend at least one inch (25 mm) from the servicing port 
and shall be replaced if removed. This use condition is the same as 
what currently exists for HFC-32 in this end-use category.
    The amendment to the regulatory text in appendix R is to indicate 
that the use conditions finalized apply to HFC-32 self-contained room 
AC units manufactured on or after the effective date of this final 
rule, May 30, 2023. Equipment manufactured before the effective date of 
the final rule is not affected by this action and is hence subject to 
the use conditions included in appendix R at the time they were 
manufactured. The finalized revisions to the current regulatory text 
update the use conditions that were included in the previous listing 
decision for HFC-32 in self-contained room ACs and HPs. EPA notes that 
there may be other requirements pertaining to the manufacture, use, 
handling, and disposal of the refrigerants that are not included in the 
information listed in the tables (e.g., the CAA section 608(c)(2) 
venting prohibition,\4\ or Department of Transportation requirements 
for transport of flammable gases). Flammable refrigerants being 
recovered or otherwise disposed of from residential and light AC 
appliances are likely to be hazardous waste under RCRA (see 40 CFR 
parts 260-270).
6. How do the updated use conditions differ from the previous 
requirements and why is EPA finalizing the change to the use 
conditions?
    For manufacturers that adhere to UL 60335-2-40, 3rd Edition, the 
updated use conditions EPA is finalizing are similar to the ones that 
already exist in

[[Page 26397]]

appendix R of 40 CFR part 82, subpart G for HFC-32 in this end-use 
category. The final requirements that HFC-32 must be used in new 
equipment only and must include red markings at service ports are 
repeated in this final listing. Existing room ACs using HFC-32 
manufactured before the effective date of this final rule are not 
affected by the updated use conditions. In addition, manufacturers may 
opt to continue to adhere to the requirements in UL 484, 8th Edition up 
to and including its sunset date of January 1st, 2024. After this date, 
the use conditions that require adherence solely with UL 60335-2-40, 
3rd Edition, described below and in greater detail in section II.E.1, 
will be mandatory for all relevant equipment.
    The warning labels EPA is finalizing for the use of HFC-32 in self-
contained room ACs and HPs designed to conform with UL 60335-2-40 are 
similar to those required as use conditions for the use of HFC-32 in 
residential and light commercial AC and HPs (excluding self-contained 
room ACs and HPs) and for R-452B, R-454A, R-454B, R-454C, and R-457A in 
residential and light commercial AC and HPs (including self-contained 
room ACs and HPs), included in SNAP Rule 23 in 2021 (86 FR 24463; May 
6, 2021). EPA finds that using a common set of labels will aid in 
compliance, especially for a manufacturer that uses more than one of 
these refrigerants or produces both self-contained room ACs and HPs and 
other types of residential and light commercial AC and HPs. The updated 
label options EPA is finalizing use the word ``WARNING'' in lieu of 
``DANGER'' or ``CAUTION'' and change ``Risk of Fire or Explosion'' to 
just ``Risk of Fire.'' However, the previous wording consistent with UL 
484, 8th Edition is allowable up to and including January 1st, 2024 for 
manufacturers who would prefer transitioning to UL 60335-2-40, 3rd 
Edition at a date later than the effective date of this final rule. EPA 
is finalizing that the labels must be provided in letters no less than 
6.4 mm (\1/4\ inch) high and must be permanent, which is identical to 
the current requirement for HFC-32 in self-contained room ACs and HPs. 
In contrast, for manufacturers choosing to continue to make self-
contained room ACs and HPs using R-32 according to Appendix SA and 
Appendices B through F of the 8th edition of UL 484 up to and including 
January 1st, 2024, rather than making such equipment according to UL 
60335-2-40, the existing labeling requirements in appendix R to 40 CFR 
part 82, subpart G (listing 10) will continue to apply.
    EPA is updating the standard incorporated by reference in the use 
conditions, requiring users either to follow certain sections of the 
2012 version of UL 484 or to adhere to the 3rd edition of UL 60335-2-
40. Both UL Standard 484 and UL Standard 60335-2-40 were developed in 
an open and consensus-based approach, with the assistance of experts in 
the refrigeration and AC industry as well as experts involved in 
assessing the safety of products. The revision cycle for the 3rd 
edition, including final recirculation, concluded with its publication 
on November 1, 2019. The 2019 UL Standard overlaps with, and eventually 
will replace, the previously published version of several standards, 
including UL Standard 484, 8th Edition on January 2nd, 2024. EPA was 
aware of the continuing progress of UL Standards to address flammable 
refrigerants more appropriately. In the 2021 SNAP Rule (SNAP Rule 23) 
listing HFC-32 for other categories within the residential and light 
commercial AC and HPs end-use, we stated, ``EPA understands that the 
standard we relied on in [SNAP] Rule 19 might `sunset' in the future. 
Therefore, we will continue to evaluate the market for the equipment 
addressed in that rule, including HFC-32 in self-contained room ACs, 
and whether to establish new or revised use conditions that reference 
UL 603352-40'' (86 FR 24463; May 6, 2021). Today, we are finalizing 
such a change knowing that UL is replacing the standard to which such 
equipment is certified from UL 484 to the newer UL 60335-2-40 standard 
as of January 2nd, 2024. In addition, in order to allow manufacturers 
more time to transition their product lines from the earlier UL 484 
standard to the UL 60335-2-40 standard, while still ensuring the safety 
of equipment manufactured with flammable refrigerants, EPA is allowing 
self-contained room ACs and HPs manufactured with HFC-32 to follow 
either standard up to and including January 1st, 2024.
    Updating the UL standard incorporated as a use condition will allow 
more consistency among the products within this end-use and between 
HFC-32 and the five A2L refrigerants listed as acceptable, subject to 
use conditions, for this end-use including those listed for self-
contained room ACs and HPs in SNAP Rule 23. This change will allow the 
industry to focus on the more recent standard. The change will be 
helpful in implementing any transitions needed or planned for 
manufacturers, installers, and technicians. A manufacturer, who may 
offer different products within this end-use with different 
refrigerants, could use similar processes, such as in developing and 
applying the warning labels required. Installers and technician, 
likewise, would not need to reference different standards depending on 
the type of equipment and the particular A2L refrigerant being used in 
that equipment, when putting in a new piece of equipment or servicing 
that equipment.
    Another revision to the use conditions is charge sizes. In the 2019 
SNAP Rule, charge sizes from both UL 484, 8th Edition, and those 
stipulated by tables within the rule needed to be followed. These will 
both continue to be requirements for equipment designed according to UL 
484, 8th Edition. However, for equipment designed according to the 3rd 
edition of UL 60335-2-40, rather than requiring examination of both 
items and determining which charge size is lower, the updated use 
conditions will rely on a single document, UL 60335-2-40, 3rd Edition. 
As stated above, manufacturers will be allowed to select which standard 
they would like their equipment to follow, up to and including the UL 
484, 8th Edition sunset date of January 1st, 2024, and equipment will 
be considered in compliance if their charge sizes are determined either 
by UL 60335-2-40, 3rd Edition or by UL 484, 8th Edition in combination 
with the tables in 40 CFR part 82, subpart G, appendix R.
7. What is the acceptability status of HFC-32 in self-contained room 
ACs and HPs?
    The use conditions finalized in this action apply to new self-
contained room ACs and HPs using HFC-32 manufactured on or after the 
effective date of this final rule (30 days after publication in the 
Federal Register). This final rule does not apply to or affect 
equipment manufactured before the effective date of this action and 
manufactured in compliance with the SNAP requirements applicable at the 
time of manufacture. For the purposes of the SNAP program, EPA views 
equipment to be manufactured when the appliance's refrigerant circuit 
is complete, the appliance can function, the appliance holds a full 
refrigerant charge, and the appliance is ready for use for its intended 
purposes. Self-contained room ACs and HPs are factory charged, meaning 
manufacture happens in the factory and thus prior to distribution in 
U.S. commerce. For such products manufactured between May 11, 2015, and 
the effective date of this final rule, the applicable use conditions 
under SNAP would be those in SNAP

[[Page 26398]]

Rule 19 (which took effect May 11, 2015) and as listed in appendix R of 
40 CFR part 82, subpart G (listing 6. Such products are permitted to be 
warehoused and sold in U.S. commerce, as long as the products were 
manufactured (i.e., the refrigerant circuit was complete) before May 
30, 2023. For self-contained room ACs and HPs using HFC-32 manufactured 
on or after the effective date of this final rule and through January 
1, 2024, the use conditions finalized and listed in the revisions to 
appendix R (either listing 6, if following UL 484, or listing 8 if 
following UL 60335-2-40) would apply under SNAP. For self-contained 
room ACs and HPs using HFC-32 manufactured on or after January 2, 2024, 
the use conditions finalized in listing 8, including following UL 
60335-2-40, will apply under SNAP, recognizing that UL intends to 
sunset UL 484 as of January 1, 2024.
8. What additional information is EPA including in these final 
listings?
    EPA is providing additional information related to these final 
listings. Since this additional information is not part of the 
regulatory decision under SNAP, these statements are not binding for 
use of the substitute under the SNAP program. See section II.E.2 below 
for further discussion on what additional information EPA is including 
in these final listings. EPA notes that the additional information is 
similar to, but not identical with, the additional information in the 
listing for HFC-32 in self-contained room ACs and HPs in SNAP Rule 19. 
EPA is finalizing additional information consistent with that included 
in the other final listings for air conditioning equipment in this rule 
and consistent with that included in the listings for four A2L 
refrigerant blends listed as acceptable subject to use conditions in 
self-contained room ACs and HPs in SNAP Rule 23. While the items listed 
are not legally binding under the SNAP program, EPA encourages users of 
substitutes to apply all statements in the ``Further Information'' 
column in their use of these substitutes as best practices for safer 
use.
9. How is EPA responding to comments on updating use conditions for 
HFC-32 in self-contained room ACs and HPs?
    Comment: AHAM, GE Appliances, and LG Electronics all submitted 
comments that the omission of a transition period between the use 
conditions requiring the UL 484 standard and the UL 60335-2-40 standard 
is inappropriate, and they request an overlapping timeframe when either 
of the two standards may be used. GE Appliances stated that 
manufacturers need time to convert products and manufacturing 
facilities when moving from compliance with one standard to the other. 
Similarly, AHAM stated that, regardless of the final rule's effective 
date, EPA must ``allow for some overlap of acceptable use conditions to 
allow for product conversion because the absence of this overlap places 
exceptional burden on appliance manufacturers,'' and noted that there 
are currently home comfort products on the market based on prior use 
conditions under SNAP Rule 19. In AHAM's words, ``EPA needs to keep 
multiple versions of these standards available for products to allow 
manufacturers time to transition from one standard to another as they 
do under the current standards certification process.'' GE Appliances 
noted that the phaseout of UL 484 and transition to the new standard 
has already been determined by UL to be January 1st, 2024. Competition 
Advocates requested that EPA revise its proposed SNAP Rule 25 use 
conditions to allow for an extended implementation time. LG Electronics 
supported EPA's action but noted that there is no time for product 
conversion from UL 484 to UL 60335-2-40 under the proposed SNAP Rule 
25. LG Electronics suggested that EPA should allow for some overlap of 
use conditions to allow for product conversion, so that manufacturers 
can comply with relevant safety standards.
    AHRI suggested that EPA may want to consider an example of the 
process for sunsetting standards used by nationally recognized testing 
laboratories (NRTLs). They said that NRTLs will test and list equipment 
to various versions of standards starting at an agreed-upon date, and 
that there may be a transition period of several years until an older 
standard is sunset. AHRI also stated that existing equipment remains 
listed to existing safety standards until the manufacturer requests to 
have it changed, that equipment with major revisions is treated as 
``new'' equipment, and that equipment with minor revisions does not 
require re-evaluation. AHRI stated that this would ensure that 
equipment can still be listed to these standards, taking care to avoid 
creating a cumbersome additional process to re-harmonize among 
companies and all of the NRTLs.
    Daikin commented that they fully support the provision of the 
proposal to update use conditions for HFC-32 to allow warning labels in 
line with UL 60335-2-40 to eliminate the disparity between the warning 
use condition for HFC-32 PTACs (listed in SNAP Rule 19) and the other 
SNAP-approved A2L PTACs, listed in SNAP Rule 23.
    Response: EPA thanks the commenters for bringing to our attention 
the necessity of a transition period where either UL 484, 8th Edition 
or UL 60335-2-40, 3rd Edition could apply. EPA agrees with commenters 
that only allowing 30 days to transition from one standard to another 
is insufficient, given equipment production timelines and challenges 
associated with updating equipment on short notice. Further, we note 
that both standards address the potential hazards of using flammable 
refrigerants, allowing HFC-32 to be used as safely as other 
refrigerants in this end-use. Therefore, to offer manufacturers time 
for product conversion, we are providing a transition period where 
either standard may be used. EPA is finalizing that, as of the 
effective date of this final rule, both compliance with UL 484 and 
compliance with the 3rd edition of UL 60335-2-40 will be acceptable 
until January 1st, 2024, when the UL 484 standard sunsets. The overlap 
of these standards will provide manufacturers time to transition from 
one standard to the next, including the different warning labels. This 
differs from the proposed use conditions, which proposed compliance 
with only UL 60335-2-40 warning labels as of this final rule's 
effective date. Beginning January 2nd, 2024, compliance with UL 60335-
2-40 will apply, given that January 1st, 2024, is the official sunset 
date of UL 484 per UL. After that date, only the UL 60335-2-40 standard 
applies under SNAP.
    EPA appreciates the information provided by AHRI on the process for 
``sunsetting standards used by NRTLs,'' and we agree that it is 
important to have a pathway to compliance as new standards become 
available. EPA believes that adopting the same sunset date as UL will 
provide the greatest clarity for industry on how long UL 484 will be 
applicable under SNAP.
    EPA acknowledges Daikin's support of the proposal to update the 
warning label use conditions for the existing listing of HFC-32 in 
self-contained room ACs and HPs, originally listed in SNAP Rule 19.
    Comment: Daikin submitted comment on ignition sources for self-
contained HFC-32 AC and HP units referenced in SNAP Rule 19 use 
conditions, stating that ``The ignition source examples that EPA cites 
in the quoted language [e.g., static electricity, a spark resulting 
from a closing door, or a cigarette] in the preceding sentence are 
incorrect.''
    Response: EPA acknowledges Daikin's comment regarding ignition 
sources for

[[Page 26399]]

self-contained HFC-32 AC and HP units referenced in the preamble for 
the original listing published in SNAP Rule 19. The examples of 
ignition sources that Daikin cites were appropriate for certain ASHRAE 
34 classified A3 hydrocarbon refrigerants in the context of SNAP Rule 
19 listings. Given that HFC-32 is classified as an A2L, Daikin is 
correct that static electricity, a spark resulting from a closing door, 
or a cigarette are not considered sufficient to be ignition sources for 
it. HFC-32 and other A2L refrigerants require a higher amount of energy 
to ignite than A3 refrigerants. Examples of ignition sources with 
enough energy to ignite an A2L refrigerant, found empirically, are a 
hot wire at 800 [deg]C or open flames such as from a butane lighter or 
a lit candle coming into contact directly with a refrigerant leak (Kim 
and Sunderland, 2018).\39\ This experiment also found that many other 
potential ignition sources are insufficient to ignite HFC-32 and 
certain other A2L refrigerants, such as cigarettes, electric plug and 
receptacle, friction sparks, hair dryers, and space heaters. In 
response to Daikin's comment, EPA has changed the language in the 
preamble for this final rule from the July 2022 NPRM for HFC-32 in new 
self-contained room ACs and HPs in section II.D, above, to reflect more 
appropriate ignition sources for HFC-32. We are now clarifying the 
characterization of the A2L ignition source that we provided in the 
preamble for the original listing in SNAP Rule 19 and the NPRM for this 
final rulemaking. That clarification does not affect EPA's view that 
the final use conditions for HFC-32 described above are appropriate.
---------------------------------------------------------------------------

    \39\ Dennis Kim and Peter Sunderland, ``Viability of Various 
Ignition Sources to Ignite A2L Refrigerant Leaks,'' 17th 
International Refrigeration and Air Conditioning Conference at 
Purdue University, July, 2018. Available online at: https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2885&context=iracc.
---------------------------------------------------------------------------

E. Use Conditions and Further Information in Final Listings for 
Chillers, Residential Dehumidifiers, and HFC-32 in Self-Contained Room 
ACs and HPs

1. What use conditions is EPA finalizing and why?
    As described above, EPA is listing:

 HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-454C as 
acceptable, subject to use conditions, for use in centrifugal and 
positive displacement chillers for new equipment in comfort cooling 
applications, including commercial AC and IPAC
 HFO-1234yf, HFC-32, R-452B, R-454A, R-454B, and R-454C as 
acceptable, subject to use conditions, for use in residential 
dehumidifiers for new equipment

    In addition, EPA is finalizing revisions to the use conditions that 
apply to the listing of:

     HFC-32 as acceptable, subject to use conditions, for use 
in self-contained room ACs and HPs for new equipment

    These use conditions are summarized in the listings under 
subheadings II.A and II.B and the revisions to the use conditions are 
summarized under subheading II.D, above, and are explained here in 
greater detail. The use conditions EPA is finalizing (either as new 
listings or revisions to a previous listing) include conditions 
requiring use of each refrigerant in new equipment, which can be 
specifically designed for the refrigerant; use consistent with the UL 
60335-2-40 industry standard, 3rd Edition, including testing, charge 
sizes, ventilation, usage space requirements, and certain hazard 
warnings and markings; and requirements for warning labels and markings 
on equipment to inform consumers and technicians of potential 
flammability hazards. The listings with specific use conditions are 
intended to allow for the use of these lower flammability refrigerants 
in a manner that will ensure they do not pose a greater overall risk to 
human health and the environment than other substitutes in these end-
uses.
New Equipment Only; Not Intended for Use as a Retrofit Alternative
    EPA is finalizing that these refrigerants may be used only in new 
equipment which has been designed to address concerns unique to 
flammable refrigerants--i.e., none of these substitutes may be used as 
a conversion or ``retrofit'' refrigerant for existing equipment. The 
information that EPA has considered in our review of flammability risks 
of this refrigerant in this end-use is based on designing and testing 
new equipment and not on mitigation methods specific to retrofitting of 
existing equipment designed for non-flammable refrigerants. Neither the 
submitters nor public commenters suggested that EPA should consider 
listing the refrigerants covered by this rule for chillers, 
dehumidifiers, or self-contained room ACs and HPs for retrofit use. 
Therefore, EPA is finalizing that they may only be used in new 
equipment which can be properly designed for their use. This use 
condition does not affect the ability to service a system using the 
refrigerant once installed, including the adding of refrigerant or 
replacing components.
    This use condition would not affect the ability to service a system 
using one of these refrigerants once installed, including the adding of 
refrigerant or replacing components.
Standards
    EPA is finalizing that the flammable refrigerants may be used only 
in equipment that meets all requirements in UL Standard 60335-2-40, 3rd 
Edition.
    Those participating in the UL 60335-2-40 consensus standards 
process have tested equipment for flammability risk and evaluated the 
relevant scientific studies. Further, UL has developed safety standards 
including requirements for construction and system design, for 
markings, and for performance tests concerning refrigerant leakage, 
ignition of switching components, surface temperature of parts, and 
component strength after being scratched. Certain aspects of system 
construction and design, including charge size, ventilation, and 
installation space, and greater detail on markings, are discussed 
further below in this section. The UL 60335-2-40 Standard was developed 
in an open and consensus-based approach, with the assistance of experts 
in the AC industry as well as experts involved in assessing the safety 
of products. While similar standards exist from other bodies such as 
the International Electrotechnical Commission (IEC), we are finalizing 
to rely on specific UL standards that are most applicable and 
recognized by the U.S. market. This approach is the same as that in our 
previous rules on flammable refrigerants (e.g., 76 FR 78832; December 
20, 2011, 80 FR 19454; April 10, 2015, and 86 FR 24444; May 6, 2021).
    A summary of the requirements of UL 60335-2-40 as they affect the 
refrigerants and end-use addressed in this section of our rule follows. 
This summary is offered for information only and does not provide a 
complete review of the requirements in this standard.
    Among the provisions in UL 60335-2-40 are limits on the amount of 
refrigerant allowed in each type of appliance based on several factors 
explained in that standard. The requirements in UL 60335-2-40 reduce 
the risk to workers and consumers. Annex GG of the standard provides 
the charge limits, ventilation requirements and requirements for 
secondary circuits. The standard specifies requirements for 
installation space of an appliance (i.e., room floor area) and/or 
ventilation or other requirements that are determined according to the 
refrigerant charge used

[[Page 26400]]

in the appliance, the installation location and the type of ventilation 
of the location or of the appliance. Within Annex GG, Table GG.1 
provides guidance on how to apply the requirements to allow for safe 
use of flammable refrigerants. UL 60335-2-40, 3rd Edition contains 
provisions for safety mitigation. These mitigation requirements were 
developed to ensure the safe use of flammable refrigerants over a range 
of appliances. In general, as larger charge sizes are used, more 
stringent mitigation requirements are required by the standard. In 
certain applications, refrigerant detection systems (as described in 
Annex LL, Refrigerant detection systems for A2L refrigerants) and 
refrigerant sensors (as described in Annex MM, Refrigerant sensor 
location confirmation tests) such as safety alarms are required by the 
standard. Where air circulation (i.e., fans) is required in accordance 
with Annex GG or Annex 101.DVG, it must be initiated by a separate 
refrigerant detection system either as part of the appliance or 
installed separately. In a room with no mechanical ventilation, Annex 
GG provides requirements for openings to rooms based on several 
factors, including the charge size and the room area. The minimum 
opening is intended to be sufficient so that natural ventilation would 
reduce the risk of using a flammable refrigerant. The standard also 
includes specific requirements covering construction, instruction 
manuals, allowable charge sizes, mechanical ventilation, safety alarms, 
and shut off valves for A2L refrigerants.
    In addition to Annex GG and Table GG.1 mentioned above, UL 60335-2-
40 has a requirement for the maximum charge for an appliance using an 
A2L refrigerant. Additional requirements exist for charge sizes 
exceeding three times the LFL.
    Table GG.1 of the UL standard indicates that systems with 
refrigerant charges exceeding certain amounts are outside the scope of 
the standard, stating that ``National standards apply.'' Specifically, 
if the refrigeration circuit with the greatest mass of a flammable 
refrigerant is more than 260 times the lower flammability limit (in kg/
m\3\), such equipment is outside the scope. For example, HFC-32 has an 
LFL of approximately 0.307 kg/m\3\ (0.0192 lb/ft\3\); therefore, 
equipment with charge sizes of a single circuit exceeding 79.82 kg 
(176.0 lb) would fall outside the scope of the UL Standard. EPA expects 
that many chillers could exceed these charge thresholds and therefore 
is proposing that an additional safety standard would apply for all 
chillers, as discussed in section II.A.4, above. EPA does not expect 
this situation to occur for residential dehumidifiers or self-contained 
room ACs and HPs because of their smaller charge sizes.
    EPA recognizes that an updated edition of this standard, Edition 4, 
was published on December 17, 2022. Nevertheless, EPA is finalizing 
this rulemaking to the 3rd Edition of this standard because the 4th 
Edition was not available ahead of the issuance of the proposed rule 
for the Agency to consider. Therefore, since the 4th Edition was 
published several months after the proposed rule and after the close of 
the comment period, EPA could not have reviewed the standard for 
inclusion in the proposal and there was no opportunity for public 
comment on whether to incorporate it into the use conditions for these 
listings. EPA intends to review the 4th edition and if appropriate, EPA 
will propose to update the use conditions contained in this final rule 
in a subsequent rulemaking.
Warning Labels
    EPA is requiring labeling of chillers and residential 
dehumidifiers. In addition, EPA is modifying the previously promulgated 
use conditions for HFC-32 self-contained room ACs and HPs 
(``equipment'') to update the warning label text. EPA is finalizing 
that the following labels, or the equivalent, must be provided in 
letters no less than 6.4 mm (\1/4\ inch) high and must be permanent 
(except for HFC-32 self-contained equipment opting to follow the 
current use conditions in compliance with UL 484, 8th Edition up to and 
including its sunset date of January 1st, 2024):

i. On the outside of the equipment: ``WARNING--Risk of Fire. Flammable 
Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do 
Not Puncture Refrigerant Tubing''
ii. On the outside of the equipment: ``WARNING--Risk of Fire. Dispose 
of Properly In Accordance With Federal Or Local Regulations. Flammable 
Refrigerant Used''
iii. On the inside of the equipment near the compressor: ``WARNING--
Risk of Fire. Flammable Refrigerant Used. Consult Repair Manual/Owner's 
Guide Before Attempting to Service This Product. All Safety Precautions 
Must Be Followed''
iv. For any equipment pre-charged at the factory, on the equipment 
packaging or on the outside of the equipment: ``WARNING--Risk of Fire 
due to Flammable Refrigerant Used. Follow Handling Instructions 
Carefully in Compliance with National Regulations''
1. If the equipment is delivered packaged, this label shall be applied 
on the packaging
2. If the equipment is not delivered packaged, this label shall be 
applied on the outside of the appliance

    EPA expects that all residential dehumidifiers and all self-
contained room ACs and HPs would be packaged, and hence this label 
would be placed as stipulated in item 1 above. For self-contained room 
ACs and HPs that are opting to continue being manufactured according to 
UL 484, 8th Edition, the existing labeling requirements apply until the 
standard sunsets on January 1, 2024, and are described in the section 
below. EPA expects that chillers could be provided packaged or not, and 
this label would be placed as stipulated in item 1 or 2, respectively.

v. On the equipment near the nameplate:
1. At the top of the marking: ``Minimum installation height, X m (W 
ft).'' This marking is only required if the similar marking is required 
by the 3rd Edition of UL 60335-2-40. The terms ``X'' and ``W'' shall be 
replaced by the numeric height as calculated per the UL Standard. Note 
that the formatting here is slightly different than the UL Standard; 
specifically, the height in Inch-Pound units is placed in parentheses 
and the word ``and'' has been replaced by the opening parenthesis.
2. Immediately below v.1. above or at the top of the marking if v.1. is 
not required: ``Minimum room area (operating or storage), Y m\2\ (Z 
ft\2\).'' The terms ``Y'' and ``Z'' shall be replaced by the numeric 
area as calculated per the UL Standard. Note that the formatting here 
is slightly different than the UL Standard; specifically, the area in 
Inch-Pound units is placed in parentheses and the word ``and'' has been 
replaced by the opening parenthesis.
vi. For non-fixed equipment, including residential dehumidifiers and 
self-contained room ACs and HPs, on the outside of the product: 
``WARNING--Risk of Fire or Explosion--Store in a well-ventilated room 
without continuously operating flames or other potential ignition.'' 
EPA expects that this label would be required on residential 
dehumidifiers, non-residential dehumidifiers, and HFC-32 self-contained 
room ACs (e.g., including portable ACs, window ACs, PTACs and PTHPs).
vii. For fixed equipment that is ducted, near the nameplate: 
``WARNING--Risk of Fire--Auxiliary devices which may be ignition 
sources shall not be

[[Page 26401]]

installed in the ductwork, other than auxiliary devices listed for use 
with the specific appliance. See instructions.''

    The text of the warning labels, above in i. through iv., vi., and 
vii., is exactly the same as that required in UL 60335-2-40, while the 
text of the label identified in v. is similar to that in the UL 
Standard. The major difference between this rule's warning label 
requirements and the requirements in Table 101.DVF.1 of UL 60335-2-40 
is that the markings for A2L refrigerants, including HFO-1234yf, HFC-32 
and the four refrigerant blends, are required to be no less than 3.2 mm 
(\1/8\ inch) high in the standard instead of 6.4 mm (\1/4\ inch) as EPA 
is finalizing in this action. EPA considers it difficult to see warning 
labels with the minimum lettering height requirement for A2L 
refrigerants of 3.2 mm (\1/8\ inch) in the UL Standard. Therefore, as 
in the requirements in our previous flammable refrigerants rules (e.g., 
76 FR 78832; December 20, 2011 and 80 FR 19454; April 10, 2015 and 86 
FR 24444; May 6, 2021), EPA is finalizing that the minimum height for 
lettering must be 6.4 mm (\1/4\ inch) as opposed to 3.2 mm (\1/8\ 
inch), which will make it easier for technicians, consumers, retail 
storeowners, first responders, and those disposing the appliance to 
view the warning labels.
    For those manufacturers of new self-contained room ACs and HPs 
opting to follow the UL 484, 8th Edition standard up to and including 
its sunset date of January 1st, 2024, EPA is finalizing that the 
following markings, or the equivalent, must be provided in letters no 
less than 6.4 mm (\1/4\ inch) high and must be permanent:
    (a) On the outside of the air conditioner: ``DANGER--Risk of Fire 
or Explosion. Flammable Refrigerant Used. To Be Repaired Only By 
Trained Service Personnel. Do Not Puncture Refrigerant Tubing.''
    (b) On the outside of the air conditioner: ``CAUTION--Risk of Fire 
or Explosion. Dispose of Properly In Accordance With Federal Or Local 
Regulations. Flammable Refrigerant Used.''
    (c) On the inside of the air conditioner near the compressor: 
``CAUTION--Risk of Fire or Explosion. Flammable Refrigerant Used. 
Consult Repair Manual/Owner's Guide Before Attempting To Service This 
Product. All Safety Precautions Must Be Followed.''
    (d) On the outside of each portable air conditioner: ``WARNING: 
Appliance shall be installed, operated and stored in a room with a 
floor area larger the ``X'' m\2\ (Y ft\2\).'' The value ``X'' on the 
label must be determined using the minimum room size in m\2\ calculated 
using Appendix F of UL 484, 8th Edition.
    However, after the sunset of UL 484 on January 1st, 2024, the use 
conditions described above, related to the 3rd edition of UL 60335-2-
40, will apply for all self-contained room ACs and HPs under SNAP.
Markings
    Our understanding of the UL Standard is that red markings, similar 
to those EPA has applied as use conditions in past actions for 
flammable refrigerants (76 FR 78832; December 20, 2011 and 80 FR 19454; 
April 10, 2015 and 86 FR 24444; May 6, 2021), are required by the UL 
Standard for A2 and A3 refrigerants but not A2L refrigerants. EPA is 
finalizing that such markings apply to these A2L refrigerants as well, 
to establish a common, familiar and standard means of identifying the 
use of a flammable refrigerant.
    These red markings will help technicians immediately identify the 
use of a flammable refrigerant, thereby potentially reducing the risk 
of using sparking equipment or otherwise having an ignition source 
nearby. The AC and refrigeration industry currently uses red-colored 
hoses and piping as means for identifying the use of a flammable 
refrigerant based on previous SNAP listings. Likewise, distinguishing 
coloring has been used elsewhere to indicate an unusual and potentially 
dangerous situation, for example in the use of orange-insulated wires 
in hybrid electric vehicles. Currently under the SNAP listings, as 
applicable, color-coded hoses or pipes must be used for ethane, HFC-32, 
R-452B, R-454A, R-454B, R-454C, R-457A, isobutane, propane, and R-441A 
in certain types of equipment where these are listed acceptable, 
subject to use conditions. All such tubing must be colored red PMS #185 
or RAL 3020 to match the red band displayed on the container of 
flammable refrigerants AHRI Guideline N, ``2017 Guideline for 
Assignment of Refrigerant Container Colors.'' The intent of this 
requirement is to provide adequate notice for technicians and others 
that a flammable refrigerant is being used within a particular piece of 
equipment or appliance. Another goal is to provide adequate 
notification of the presence of flammable refrigerants for personnel 
disposing of appliances containing flammable refrigerants. As explained 
in a previous SNAP rule, one mechanism to distinguish hoses and pipes 
is to add a colored plastic sleeve or cap to the service tube. (80 FR 
19465; April 10, 2015). Other methods, such as a red-colored tape could 
be used. The colored plastic sleeve, cap, or tape would have to be 
forcibly removed in order to access the service tube and would have to 
be replaced if removed. This would signal to the technician that the 
refrigeration circuit that she/he was about to access contained a 
flammable refrigerant, even if all warning labels were somehow removed. 
This sleeve, cap or tape would be of the same red color (PMS #185 or 
RAL 3020) and could also be boldly marked with a graphic to indicate 
the refrigerant was flammable. This could be a cost-effective 
alternative to painting or dyeing the hose or pipe.
    EPA is finalizing the use of color-coded hoses or piping as a way 
for technicians and others to recognize that a flammable refrigerant is 
used in the equipment. This would be in addition to the proposed use of 
warning labels discussed above. EPA considers having two such warning 
methods to be reasonable and consistent with other general industry 
practices. This approach is the same as that adopted in our previous 
rules on flammable refrigerants (e.g., 76 FR 78832; December 20, 2011 
and 80 FR 19454; April 10, 2015 and 86 FR 24444; May 6, 2021).
2. What additional information is EPA including in these final 
listings?
    For chillers, residential dehumidifiers, and self-contained room 
ACs and HPs, EPA is including additional information, found in the 
``Further Information'' column of the regulatory text at the end of 
this document, to protect personnel from the risks of using flammable 
refrigerants. Similar to our previous listings of flammable 
refrigerants, EPA is including information on the OSHA requirements at 
29 CFR part 1910, proper ventilation, personal protective equipment, 
fire extinguishers, use of spark-proof tools and equipment designed for 
flammable refrigerants, and training. Since this additional information 
is not part of the regulatory decision under SNAP, these statements are 
not binding for use of the substitute under the SNAP program. While the 
items listed are not legally binding under the SNAP program, EPA 
encourages users of substitutes to apply all statements in the 
``Further Information'' column in their use of these substitutes as 
best practices for safer use.

[[Page 26402]]

3. How is EPA responding to comments on use conditions and further 
information for chillers, residential dehumidifiers, and HFC-32 self-
contained room ACs and HPs?
    Comment: Several commenters (AHRI, the Alliance for Responsible 
Atmospheric Policy (the Alliance), Anden, AprilAire, AHAM, ATMOsphere, 
Carrier Global Corporation, Competition Advocates, Daikin, Diversified 
CPC International, the Environmental Investigation Agency (EIA), GE 
Appliances/Haier, LG Electronics U.S.A., Chemours, Trane, UL Solutions) 
commented in support of incorporating by reference the industry 
standards UL 60335-2-40 and ASHRAE 15 into the use conditions for 
chillers, residential dehumidifiers, and self-contained room AC and 
HPs, but expressed concerns on the Agency's timing of referencing 
specific editions of these standards.
    AHRI, Chemours, and UL stated that a new version of UL 60335-2-40, 
the 4th edition, may soon be published. Carrier and Daikin recommended 
using the 4th edition of UL 60335-2-40 instead of the proposed 3rd 
edition of that standard if the 4th edition is published before EPA 
issues a final rulemaking. EIA, an environmental group, stated that the 
4th Edition of UL 60335-2-40 should be used in the final rule's use 
conditions if published before EPA takes final action on this rule. 
Trane recommended delaying approval of SNAP Rule 25 as it relates to 
chillers, until it can incorporate by reference the 4th Edition of UL 
60335-2-40. UL stated that the 4th edition has many improvements over 
the 3rd edition, including updates requested by the fire service 
community. Anden and AprilAire both suggested EPA allow for use of the 
3rd edition ``in addition to'' the 4th edition, rather than ``in lieu 
of'' the 4th edition, as EPA proposed. Chemours and Carrier suggested 
that EPA update previous rules with older editions of standards (e.g., 
SNAP Rule 23).
    Some commenters, such as Daikin and Chemours, noted that the 2022 
version of ASHRAE 15 was likely to be published a few months after the 
NPRM and before the final rule would be issued. UL mentioned the 
pending publication of ASHRAE 15-2022, in addition to the May of 2022 
version of ASHRAE 15.2, a new residential version of the standard. 
Chemours and Carrier also stated that once the new versions of the UL 
60335-2-40 and ASHRAE 15 standards are published, the use conditions of 
the proposed rule should be updated.
    AHRI stated that it will be important to have a pathway to 
compliance as each new edition becomes available. LG Electronics and 
AHAM stated that NRTLs do not have a required date to comply with the 
3rd edition and expressed concern that this will cause issues in 
obtaining proper testing for the products. AHAM commented, particularly 
with respect to the use of HFC-32 in self-contained room ACs and HPs, 
that the Agency must allow for transition periods within the rule so 
that manufactured products can comply with relevant safety standards. 
The Alliance commented on their support for dealing with codes and 
standards issues raised by AHAM and AHRI. They noted this is a critical 
issue and has been a critical issue for several years now, but that 
integration of the codes and standards will allow transition schedules 
for alternatives. Competition Advocates ``encourage[d] EPA to revise 
its proposed SNAP Rule 25 use conditions to allow for an extended 
implementation time.'' Trane commented that there should be an 
expedited process for updating the linked standards to allow for ease 
of compliance and ensure the availability of the latest technologies.
    GE Appliances noted support for SNAP Rule 25 and urged EPA to move 
quickly in finalizing. AHAM urged the Agency to ``expedite finalizing 
this rule,'' referencing regulations in California limiting refrigerant 
options in dehumidifiers as of the start of 2023.
    Response: EPA thanks the commenters for their support of including 
ASHRAE 15 and UL 60335-2-40 standards in the use conditions for 
chillers, residential dehumidifiers, and self-contained ACs and HPs in 
SNAP Rule 25. EPA acknowledges the information on further developments 
in the UL 60335-2-40 standard and ASHRAE standards processes and 
realizes that new editions of both standards have been published since 
the issuance of the proposed rule and after the close of the comment 
period. After considering all the public comments on this proposal, we 
are finalizing the editions of relevant standards required by the use 
conditions for chillers, dehumidifiers, and self-contained ACs and HPs 
as proposed. EPA is incorporating by reference the 3rd edition of UL 
60335-2-40 and the 2019 edition of ASHRAE 15. The 3rd edition of UL 
60335-2-40 includes extensive revisions specifically to address 
flammability risks of A2L refrigerants and reach industry-wide 
consensus. We conclude that the 3rd edition adequately addresses the 
use of these A2L refrigerants in the equipment proposed and as 
discussed below, if the Agency determines changes are warranted, the 
Agency can do so in a future rulemaking.
    EPA is aware of the new 4th edition of UL 60335-2-40 and the ASHRAE 
15-2022 standards that have recently been published. However, these 
editions were not available in advance of the development of the 
proposed rule and thus were not considered. In addition, the public did 
not have the opportunity to review and comment on a proposed rule that 
reflected those new editions. EPA recognizes that the UL standards are 
under continuous maintenance--as are ASHRAE Standards 15 and 15.2--and 
hence may change again, even though the mentioned editions are newly 
published. Past experience suggests it is difficult to align the 
regulatory development process with these standard-setting processes. 
EPA concluded that rather than wait for the issuance of a new edition 
(which could be replaced with a subsequent edition), it was important 
for EPA to act on the SNAP submissions and propose listings based on 
the best available information, which included the available editions 
of the relevant UL and ASHRAE standards. Furthermore, now that a 4th 
edition of the UL Standard and the 2022 version of ASHRAE 15 are 
released, EPA will review the relevant changes and may develop a 
subsequent rulemaking, allowing for a notice and comment period for the 
public to provide their opinions on the updates.
    Some commenters supported moving forward with the rule using the 
3rd edition of UL 60335-2-40 consistent with EPA's proposal. EPA 
concludes that reliance on the 3rd edition of the UL Standard, the 2019 
version of ASHRAE 15, and other use conditions allows applicable 
products to be used safely. Given the comments received expressing 
desire for quick finalization of the rule, EPA's understanding that the 
3rd edition provides many desired improvements on the 2nd edition, and 
environmental benefits to providing these ODS alternatives as quickly 
as possible, EPA is finalizing to the 3rd edition of UL 60335-2-40.
    Regarding Trane's comment requesting an expedited updating process 
for standards, EPA does not have an automatic process or a process with 
fewer steps, as each particular iteration of a standard must be 
reviewed by the Agency. Additionally, updating the standard involves a 
change to regulations, and the Agency typically uses a notice-and-
comment process to change the standard that is incorporated into 
regulations. In response to comments from Chemours and Carrier

[[Page 26403]]

that EPA should also update previous rules with older editions of 
standards, EPA notes that this is outside the scope of this rulemaking. 
EPA will continue to consider changes to relevant standards, both for 
this rule and for previous rules addressing flammable refrigerants, and 
the Agency may consider whether any revisions to the SNAP program 
regulations should be proposed at a future date.
    Comment: Several commenters noted concerns regarding the proposed 
use conditions (AHRI, the Alliance, Anden, AprilAire, Competition 
Advocates, Daikin, Diversified CPC International). Anden commented on 
EPA's proposed use condition requiring ``marked service ports, pipes, 
hoses, and other devices through which the refrigerant is serviced'' 
and requested ``EPA to clarify in the final rule that this particular 
use condition does not apply to equipment that does not have service 
ports.'' Similar to Anden, AprilAire commented on ``marked service 
ports'' and requested ``EPA to clarify in the final rule that this 
particular use condition does not apply to equipment that does not have 
service ports.'' AprilAire noted that their products generally do not 
contain service ports.
    Daikin noted that ``EPA inaccurately characterized the operation of 
chillers in its general description of warning label use conditions 
``vii. For fixed equipment that is ducted, including chillers. . . .'' 
87 F.R. at 45523 (emphasis added).''
    Diversified CPC International, a producer of specialty gases, 
including hydrocarbon refrigerants, commented on the use of hydrocarbon 
refrigerants and noted it has ``been limited within the United States 
due to refrigerant charge limitations that are much lower than most 
regions in the world. For example, the IEC Standard IEC 60335-2-40 
allows for 1,000 grams charge size for indoor air conditioning units 
and a 5 kg limit for outdoor air conditioning units.'' They stated that 
EPA should consider modifying use conditions to allow compliance for 
larger A3 charge sizes for various types of equipment that falls under 
the scope of UL 60335-2-40, 3rd Edition and UL 60335-2-89, 2nd Edition. 
ATMOsphere, a trade group, stated that the next step for revising North 
American safety standards will be to form a CANENA Technical 
Harmonization Committee (THC) to discuss possibly adopting changes from 
the 7th and most recent edition of the IEC into a future edition 5 of 
UL 60335-2-40, with larger charge sizes for hydrocarbons.
    Response: The Agency acknowledges support for the proposed listings 
covered by the use conditions in this section of the preamble. After 
considering all the public comments on the proposal, we are finalizing 
these use conditions, with modifications in response to the comments 
received. A few commenters requested clarification on use conditions 
requiring ``marked service ports, pipes, hoses, and other devices 
through which the refrigerant is serviced.'' EPA considers the marked 
service port use condition to apply to equipment without service ports, 
as servicing or recovery occurs through their pipes, hoses, or other 
devices. Technicians will still need information provided by the 
service port markings in these circumstances. After considering all the 
public comments on this proposal, we are finalizing this use condition 
as proposed.
    EPA agrees with comments provided by Daikin indicating that EPA may 
have inadvertently mischaracterized the operation of chillers in its 
general description of warning label use conditions. In response to 
this comment, EPA has edited the warning label description for fixed 
equipment to keep the reference to ducted equipment and to remove the 
reference to chillers.
    EPA is aware of the larger charge sizes for hydrocarbon 
refrigerants allowed in updated versions of UL standards, such as UL 
60335-2-89, 2nd Edition and UL 60335-2-40, 3rd Edition. EPA did not 
propose to increase the charge sizes of A3 refrigerants, thus this 
request is beyond the scope of this rulemaking. Additionally, EPA did 
not consider equipment covered by the UL 60335-2-89 standard in this 
rulemaking. Any changes to use conditions for listings not included in 
the proposal are beyond the scope of this final rule, and if EPA 
concludes that proposing changes to the listings is warranted, it would 
typically initiate a separate rulemaking process. The Agency is 
familiar with the process of forming a CANENA THC to discuss proposals 
for adopting the changes in IEC 60335-2-40 Edition 7 into the next 
edition of the North American safety standards, including the 5th 
edition of UL 60335-2-40. If a 5th edition of UL 60335-2-40 is 
released, EPA can consider any relevant changes such as allowing for 
larger charge sizes for hydrocarbon refrigerants in a future 
rulemaking.

F. Very Low Temperature Refrigeration (VLTR)--Listing of R-1150 as 
Acceptable, Subject to Use Conditions and Narrowed use limits, for Use 
in New VLTR

    In the NPRM, EPA proposed to list R-1150 as acceptable, subject to 
use conditions and narrowed use limits, for use in new VLTR equipment. 
No comments were received in regard to this listing. Therefore, EPA is 
finalizing the listing of R-1150 in VLTR as proposed.
1. Background on VLTR
    The very low temperature refrigeration (VLTR) end-use includes a 
wide range of equipment types. VLTR equipment is intended to maintain 
temperatures considerably lower than for refrigeration of food (below -
62 [deg]C or -80 [deg]F). Examples of very low temperature 
refrigeration equipment include medical freezers and freeze-dryers, 
which generally require extremely reliable refrigeration cycles to 
maintain low temperatures and must meet stringent technical standards. 
In some cases, VLTR equipment may use a refrigeration system with two 
stages, each with its own refrigerant loop. This allows a greater range 
of temperatures and may reduce the overall refrigerant charge.
    For this rulemaking, only equipment designed to reach temperatures 
lower than -80 [deg]C (-112 [deg]F) is addressed. See sections II.E.6 
and II.E.7 below for a discussion of the narrowed use limits describing 
the reasoning for this temperature requirement. Examples of equipment 
covered by this final rule in the VLTR end-use include:
     Freeze dryers. This equipment typically includes a two-
stage system, with a VLTR stage being addressed by this rule and a 
warmer stage, usually classified as IPR, not addressed in this final 
rule. The primary application of this equipment is for freeze drying 
material in a laboratory setting.
     Cold traps required to operate below -80 [deg]C or -112 
[deg]F. This equipment is used during laboratory evaporation to 
condense vapors to prevent them from entering and damaging the pump, or 
leaking into the environment, ensuring a closed system within the 
vacuum pump.

[[Page 26404]]

     Very low temperature freezers designed to reach 
temperatures below -80 [deg]C or -112 [deg]F.
    This final listing decision for R-1150 addresses these types of 
equipment, as well as other types of VLTR equipment not mentioned that 
fit within the narrowed use limits described in section II.F.6, under 
SNAP. This listing addresses all types of VLTR equipment that meet the 
requirements of the UL Standard 61010-2-011, 2nd Edition, and for all 
applications of such equipment under EPA's final use conditions and 
narrowed use limits. Because UL Standard 61010-2-011 only applies to 
laboratory equipment, we understand that only VLTR equipment that is 
also laboratory equipment is eligible to use R-1150 under the use 
condition.
2. What is EPA's final listing decision for R-1150?
    EPA is listing R-1150 as acceptable, subject to use conditions and 
narrowed use limits, for use in VLTR equipment, including freeze-
dryers, cold traps, and very low temperature freezers.
3. What is R-1150 and how does it compare to other refrigerants in the 
same end-use?
    R-1150, also known as ethene or ethylene (CAS Reg. No. 75-85-1), is 
an unsaturated hydrocarbon. It is a flammable refrigerant with the 
ASHRAE safety classification A3. You may find a copy of the applicants' 
submissions, with CBI redacted, providing the required health and 
environmental information for this substitute in this end-use in Docket 
EPA-HQ-OAR-2021-0836 at https://www.regulations.gov under the names 
``Supporting Materials for Rule 25 Listing of R-1150 in Refrigeration 
and Air Conditioning. SNAP Submission Received December 3, 2018'' and 
``Supporting Materials for Rule 25 Listing of R-1150 in Refrigeration 
and Air Conditioning. SNAP Submission Received January 21, 2021.'' EPA 
performed an assessment to examine the health and environmental risks 
of this substitute. This assessment is available in Docket EPA-HQ-OAR-
2021-0836: ``Risk Screen on Substitutes in Very Low Temperature 
Refrigeration (New Equipment). Substitute: R-1150.'' \40\
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    \40\ ICF, 2022o. Risk Screen on Substitutes in Very Low 
Temperature Refrigeration (New Equipment); Substitute: R-1150.
---------------------------------------------------------------------------

    Environmental information: R-1150 has an ODP of zero and a GWP of 
four.
    In addition to ODP and GWP, EPA evaluated potential impacts of R-
1150 and other hydrocarbon refrigerants on local air quality. R-1150 is 
considered a VOC and is not excluded from EPA's regulatory definition 
of VOC (see 40 CFR 51.100(s)) for the purpose of addressing the 
development of SIPs to attain and maintain the NAAQS. As described 
below, EPA estimates that potential emissions of R-1150, when used in 
the refrigeration and AC sector in the VLTR end-use consistent with 
this listing under the SNAP program, would not have a significant 
impact on local air quality.41 42
---------------------------------------------------------------------------

    \41\ ICF, 2014. Assessment of the Potential Impact of 
Hyddrocarbon Refrigerants on Ground Level Ozone Concentrations. 
February 2014.
    \42\ ICF, 2022p. Additional Assessment of the Potential Impact 
of Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. 
May 2020.
---------------------------------------------------------------------------

    In response to the increased market share of hydrocarbon 
refrigerants, particularly in VLTR applications, EPA conducted 
additional analysis of various scenarios to consider the potential 
impacts on local air quality if hydrocarbon refrigerants were used in 
further applications.\43\ In particular, use of R-1150 in very low 
temperature freezers, including VLTR equipment with an IPR stage using 
propylene, and the use of R-1150 in retail food refrigeration systems 
\44\ were investigated for ground-level ozone effects. The analysis 
first considers highly conservative modeling scenarios where a specific 
hydrocarbon would be used widely across all end-uses in the 
refrigeration and AC sector. Scenario 1b** estimates propylene's 
emissions using EPA's Vintaging Model (VM) and Community Multi-stage 
Air Quality (CMAQ) model,\45\ and Scenario 1b estimates R-1150's 
emissions using the same VM and CMAQ versions as in Scenario 1b**.
---------------------------------------------------------------------------

    \43\ Ibid.
    \44\ EPA is aware that such refrigeration equipment exists in 
Europe. Thus, EPA evaluated R-1150 in retail food refrigeration--
stand-alone units as well as in VLTR and other hydrocarbon 
refrigerants, to consider the greatest impact that reasonably could 
occur when using increasing amounts of such refrigerants.
    \45\ VM IO file_v5.1_10.01.19 and CMAQ 5.2.1 with carbon bond 06 
(CB06) mechanism, as cited in ICF, 2022p. Additional Assessment of 
the Potential Impact of Hydrocarbon Refrigerants on Ground Level 
Ozone Concentrations. May 2020.
---------------------------------------------------------------------------

    Additionally, the analysis also considers the more realistic 
scenarios (Scenario 2, Scenario 3a, and Scenario 3b) where hydrocarbons 
are modeled only in the end-uses where the SNAP program has already 
listed them as acceptable, or for which SNAP submissions or 
international market trends indicate HCs soon could be used. Scenario 2 
examines the likely emissions of lower maximum incremental reactivity 
(MIR) hydrocarbons, propane, isobutane, and ethane, in the residential 
and light commercial AC, residential dehumidifiers, retail 
refrigeration, and household refrigeration end-uses. Scenarios 3a and 
3b also consider the use of higher MIR refrigerants propylene and R-
1150 in laboratory equipment (IPR and VLTR end-uses, respectively) and 
R-1150 in small retail food refrigeration equipment (e.g., stand-alone 
units) in addition to the hydrocarbon refrigerants used in Scenario 2. 
Scenarios 3a and 3b differentiate based on whether propylene and R-1150 
would be subject to the venting prohibition under CAA section 
608(c)(2). For further information on the specific assumptions, see the 
docket for this rulemaking.\46\
---------------------------------------------------------------------------

    \46\ ICF, 2014. Op. cit.
---------------------------------------------------------------------------

    In highly conservative Scenario 1b, examining widespread R-1150 
adoption across the entire refrigeration and AC sector, modeling 
predicts that the single 8-hour average ground-level ozone 
concentration could increase by 11.7 percent in Los Angeles, which is 
the area with the highest level of ground-level ozone pollution in the 
United States. However, the assumptions modeled in 1b are highly 
unrealistic, given the significantly smaller number of applications in 
which R-1150 has been requested for use or is currently being used 
globally. VLTR, the only end-use being addressed in this listing, 
represents a very small segment of the refrigeration and AC sector.
    In the more realistic scenarios 3a and 3b, where use of propylene 
and R-1150 in laboratory equipment and R-1150 in small retail food 
refrigeration equipment are included, the 8-hour ground-level ozone 
concentration in Los Angeles was found to increase by a maximum of 
0.017 percent relative to the NAAQS on the worst modeled day. For 
purposes of this SNAP determination, this is not a significant increase 
in ground-level ozone. The modeling is also conservative by assuming a 
one-for-one substitution of hydrocarbons for current refrigerants 
because an actual transition would likely introduce less than one 
kilogram of hydrocarbon for each kilogram replaced. As a result of this 
analysis, EPA determined that the use of R-1150 consistent with the use 
conditions and narrowed use limits finalized in this rulemaking will 
not result in significantly greater risk to people's health or the 
environment than other alternatives available for the same use.
    Ecosystem effects from R-1150 are expected to be small, as compared 
to the effects of other acceptable substitutes in

[[Page 26405]]

this end-use. R-1150 is highly volatile and typically evaporates or 
partitions to air, rather than contaminating ground or surface waters, 
and thus R-1150's effects on aquatic life are expected to be small. 
Based on these considerations, R-1150 is not expected to pose a greater 
risk of ecosystem effects than other alternatives for these uses.
    Flammability information: ASHRAE Standard 34 classifies R-1150 as a 
Class A3 refrigerant.\47\ R-1150 is flammable when its concentration in 
the air is in the range of 2.7 percent to 36 percent by volume (27,000 
ppm to 360,000 ppm).48 49
---------------------------------------------------------------------------

    \47\ ASHRAE, 2019a. Op. cit.
    \48\ Ibid.
    \49\ ICF, 2022o. Op. cit.
---------------------------------------------------------------------------

    Toxicity and exposure data: Exposure to R-1150 may be hazardous if 
inhalation, skin contact, or eye contact with the proposed substitute 
occurs at sufficiently high levels. The most likely pathway of exposure 
is through inhalation, which can cause symptoms of asphyxiation. 
Exposures of R-1150 to the skin may cause frostbite. Exposures of R-
1150 to the eyes could cause eye irritation. These potential health 
effects are common to many refrigerants.
    The American Conference of Governmental Industrial Hygienists 
(ACGIH) has established a TLV of 200 ppm as an 8-hour TWA for R-1150. 
EPA anticipates that users will be able to meet the TLV and address 
potential health risks by following the use condition limiting charge 
sizes to 150 g and the requirements and recommendations in the 
manufacturer's SDS, ASHRAE Standard 15, UL Standard 61010-2-011, 2nd 
Edition, and other safety precautions common to the refrigeration and 
AC industry.50 51
---------------------------------------------------------------------------

    \50\ ASHRAE, 2019b.
    \51\ ICF, 2022o. Op. cit.
---------------------------------------------------------------------------

    Comparison to other substitutes in this end-use: R-1150 has an ODP 
of zero, comparable to or less than other listed substitutes in this 
end-use with ODPs ranging from zero to 0.098. For new VLTR equipment, 
R-1150's GWP of four is comparable to that of other acceptable 
substitutes such as ethane and CO2, with respective GWPs of 
5.5 and one, and lower than other acceptable substitutes such as R-
410A, R-507A, and HFC-23 with respective GWPs of 1,890, 3,990, and 
14,800.
    R-1150 is a VOC that is more photochemically reactive and more 
likely to cause ground-level ozone pollution than acceptable 
refrigerants in this end-use. For example, R-1150 has a MIR of 9.07 g-
O3/g-substance, which is higher than propane's MIR of 0.56 
g-O3/g-substance or ethane's MIR of 0.28 g-O3/g-
substance.\52\ EPA addresses this potential risk through a narrowed use 
limit, restricting use of this refrigerant to VLTR equipment designed 
to reach temperatures lower than -80 [deg]C (-112 [deg]F). See section 
II.F.6 below for a discussion of the finalized narrowed use limits.
---------------------------------------------------------------------------

    \52\ In addition to being an acceptable refrigerant in very low 
temperature refrigeration, ethane's MIR is one threshold that EPA 
considers in deciding whether a compound makes a negligible 
contribution to tropospheric ozone formation and should be excluded 
from EPA's regulatory definition of VOC (see 40 CFR 51.100(s)) for 
the purpose of addressing the development of SIPs to attain and 
maintain the NAAQS.
---------------------------------------------------------------------------

    Flammability risks of R-1150 are comparable to flammability risks 
of other available substitutes in the same end-use, such as ethane, 
while R-1150's flammability risks are higher than those of nonflammable 
refrigerants such as R-410A, CO2, or HFC-23. Flammability 
risks can be addressed by following the finalized use conditions, such 
as use only in new equipment that is designed and tested to meet the UL 
Standard 61010-2-011. See section II.F.4 below for a discussion of the 
use conditions.
    Toxicity risks are comparable to or lower than toxicity risks of 
other available substitutes in the same end-use. Toxicity risks can be 
minimized by use consistent with the TLV issued by the ACGIH, ASHRAE 
Standard 15, UL 61010-2-011--which applies under the final use 
conditions--and other industry standards, recommendations in the 
manufacturer's SDS, and other safety precautions common in the 
refrigeration and AC industry.
    Although R-1150 presents a higher risk to local air quality than 
other available alternatives for this end-use, other alternatives such 
as ethane, propane, and most HFOs or HFCs, that are less 
photochemically reactive than R-1150 are not able to attain 
temperatures as low as those attainable by R-1150 because of their 
higher boiling points. Thus, EPA is finalizing listing this substitute 
as acceptable subject to use conditions and narrowed use limits in 
VLTR.
4. What use conditions is EPA finalizing?
    (1) EPA is finalizing the following use conditions to address 
flammability risks of R-1150: New equipment only--R-1150 may be used 
only in new equipment designed specifically and clearly identified for 
the refrigerant, i.e., the substitute shall not be used as a conversion 
or ``retrofit'' refrigerant for existing equipment.
    (2) UL Standard--R-1150 may be used only in laboratory equipment 
that meet all requirements listed in the 2nd edition, dated May 13th, 
2021, of UL Standard 61010-2-011, ``Safety Requirements for Electrical 
Equipment for Measurement, Control, and Laboratory Use--Part 011: 
Particular Requirements for Refrigerating Equipment.'' In cases where 
this final rule includes requirements different than those of UL 61010-
2-011, 2nd Edition, EPA is requiring that the equipment meet the 
requirements of this final rule in place of the requirements in the UL 
Standard. Requirements of note include:
     Warning labels--The following markings, or the equivalent, 
must be provided in letters no less than 6.4 millimeter (\1/4\ inch) 
high and must be permanent:
    i. Attach near the machine compartment: ``DANGER--Risk of Fire or 
Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained 
Service Personnel. Do Not Puncture Refrigerant Tubing''
    ii. Attach near the machine compartment: ``CAUTION--Risk of Fire or 
Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner's 
Guide Before Attempting To Service This Product. All Safety Precautions 
Must Be Followed.''
    iii. Attach on the exterior of the refrigeration equipment: 
``CAUTION--Risk of Fire or Explosion. Dispose of Properly In Accordance 
With Federal Or Local Regulations. Flammable Refrigerant Used.''
    iv. Attach near all exposed refrigerant tubing: ``CAUTION--Risk of 
Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow 
Handling Instructions Carefully. Flammable Refrigerant Used.''
    v. Attach on the exterior of the refrigeration equipment: ``This 
equipment is intended for use in commercial, industrial, or 
institutional occupancies as defined in the Safety Standard for 
Refrigeration Systems, ANSI/ASHRAE 15.''
    vi. Attach on the exterior of the shipping carton: ``CAUTION--Risk 
of Fire or Explosion. Dispose of Properly In Accordance With Federal Or 
Local Regulations.''
    vii. The instructions shall include the following warnings as 
necessary:
    a. ``WARNING: Ensure all ventilation openings are not obstructed.''
    b. ``WARNING: Do not use mechanical devices or other means to 
accelerate the defrosting process, other than those recommended by the 
manufacturer.''
    c. ``WARNING: Do not damage the refrigerant circuit.''

[[Page 26406]]

     Markings--Equipment must have distinguishing red (PMS #185 
or RAL 3020) color-coded hoses and piping to indicate use of a 
flammable refrigerant. The laboratory equipment shall have marked 
service ports, pipes, hoses and other devices through which the 
refrigerant is serviced. Markings shall extend at least 1 inch (25 mm) 
from the servicing port and shall be replaced if removed.
    (3) Charge size--Equipment must use no more than 150 g of R-1150 in 
each refrigerant circuit using this refrigerant.
    EPA notes that there may be other legal obligations pertaining to 
the manufacture, use, handling, and disposal of the proposed 
refrigerant that are not included in the information listed in the 
tables included in the regulatory text (e.g., the CAA section 608(c)(2) 
venting prohibition,\4\ or Department of Transportation requirements 
for transport of flammable gases). Flammable refrigerants being 
recovered or otherwise disposed of from VLTR appliances are likely to 
be hazardous waste under RCRA (see 40 CFR parts 260-270).
5. Why is EPA finalizing these specific use conditions?
    EPA is finalizing listing R-1150 as acceptable, subject to use 
conditions, for use in the VLTR end-use for new equipment reaching 
temperatures lower than -80 [deg]C (-112 [deg]F). The use conditions 
are identified in the listing under subheading II.F.4, above, and are 
explained here in greater detail. The use conditions EPA is finalizing 
include conditions requiring use of R-1150 in new equipment, which can 
be specifically designed for the refrigerant; use consistent with UL 
61010-2-011, 2nd Edition, including testing, charge sizes, ventilation, 
usage space requirements, and certain hazard warnings and markings; and 
limiting charge size to 150 g of R-1150 per refrigerant circuit. The 
finalization of these use conditions is intended to allow for the use 
of R-1150, a flammable refrigerant, in a manner that will ensure it 
does not pose a greater overall risk to human health and the 
environment than other substitutes in this end-use.
New Equipment Only; Not Intended for Use as a Retrofit Alternative
    EPA is finalizing that R-1150 may be used only in new equipment 
\53\ which has been designed to address concerns unique to flammable 
refrigerants--i.e., this substitute may not be used as a conversion or 
``retrofit'' refrigerant for existing equipment. The information that 
EPA has considered in our review of flammability risks of this 
refrigerant in this end-use is based on designing and testing new 
equipment, and not on mitigation methods specific to retrofitting of 
existing equipment designed for non-flammable refrigerants. Neither the 
submitters nor public commenters suggests that EPA should consider 
listing R-1150 for retrofit use. Therefore, EPA is finalizing that R-
1150 can only be used in new equipment properly designed for its use. 
This requirement does not affect the ability to service equipment using 
R-1150 once installed, including the adding of refrigerant or replacing 
components.
---------------------------------------------------------------------------

    \53\ This is intended to mean a completely new refrigeration 
circuit containing a new compressor, evaporator, and condenser.
---------------------------------------------------------------------------

Standards
    EPA is finalizing that R-1150 may be used only in equipment that 
meets all requirements in UL 61010-2-011, 2nd Edition. This UL standard 
indicates that refrigerant charges greater than 150 g are beyond its 
scope and that additional requirements apply, such as for instance 
ASHRAE 15-2019. EPA has only evaluated equipment that fits within the 
scope of UL 61010-2-011.
    UL has developed safety standards including requirements for 
construction and system design, for markings, and for performance tests 
concerning refrigerant leakage, ignition of switching components, 
surface temperature of parts, and component strength after being 
scratched. Certain aspects of system construction and design, including 
charge size, ventilation, and installation space, and greater detail on 
markings, are discussed further below in this section. The UL Standard 
was developed in an open and consensus-based approach, with the 
assistance of experts in the laboratory equipment industry as well as 
experts involved in assessing the safety of products. While similar 
standards exist from other bodies such as the IEC, we are finalizing to 
rely on a specific UL standard that is most applicable and recognized 
by the U.S. market. This approach is the same as that in our previous 
rules on flammable refrigerants (e.g., 76 FR 78832, December 20, 2011; 
80 FR 19454, April 10, 2015; 86 FR 24444, May 6, 2021).
    A summary of the requirements of UL 61010-2-011, 2nd Edition as 
they affect R-1150 and the end-use addressed in this section of the 
rule follows. This summary is offered for information only and does not 
provide a complete review of the requirements in this standard. UL 
61010-2-011, 2nd Edition requires the warning labels on the equipment 
to contain letters at least \1/4\ inch high. The label must be 
permanently affixed to the equipment. Warning label language 
requirements are described in section II.F.4 of this proposed rule. 
Additionally, red markings, similar to those EPA has applied as use 
conditions in past actions for flammable refrigerants (76 FR 78832, 
December 20, 2011; 80 FR 19454, April 10, 2015; 86 FR 24444, May 6, 
2021), are required by UL 61010-2-011, 2nd Edition for A2 and A3 
refrigerants to establish a common, familiar and standard means of 
identifying the use of a flammable refrigerant.
    These red markings will help technicians immediately identify the 
use of a flammable refrigerant, thereby potentially reducing the risk 
of using sparking equipment or otherwise having an ignition source 
nearby. The colored plastic sleeve or cap would have to be forcibly 
removed in order to access the service port, hose, or pipe. This would 
signal to the technician that the refrigeration circuit that she/he was 
about to access contained a flammable refrigerant, even if all warning 
labels were somehow removed. This sleeve would be of the same red color 
(PMS #185 or RAL 3020) and could also be boldly marked with a graphic 
to indicate the refrigerant was flammable. The use of a colored plastic 
sleeve or cap that is boldly marked with a graphic could be a cost-
effective alternative to painting or dyeing the service port, hose, or 
pipe.
Charge Size Limitation
    Among the provisions in UL 61010-2-011, 2nd Edition are limits on 
the amount of refrigerant allowed in each appliance. The limitations on 
refrigerant charge size for VLTR are consistent with UL 61010-2-011, 
2nd Edition to reduce the risk to workers and consumers. EPA is 
requiring a charge size limit of 150 g for each refrigerant circuit or 
stage for the proposed refrigerant. Section 1.1.1 of the UL Standard 
states, ``This document details all the requirements when up to 150 g 
of FLAMMABLE REFRIGERANT are used per stage of a REFRIGERATING SYSTEM. 
Additional requirements beyond the current scope of this document apply 
if a REFRIGERANT charge of FLAMMABLE REFRIGERANT exceeds this amount.'' 
Thus, in order to ensure the standard's provisions apply and 
sufficiently address flammability risk, EPA is requiring that each 
refrigerant circuit must contain no more than 150 g of R-1150.
    In addition to the general requirement that each refrigerant 
circuit must contain no more than 150 g of R-1150,

[[Page 26407]]

UL 61010-2-011, 2nd Edition has a requirement for the maximum charge 
for remote condensing unit using a flammable refrigerant in Annex DD 
and Table DD.1. Section DD.2.4 of Annex DD sets requirements for the 
minimum associated room area for a given charge, based on a maximum 
refrigerant concentration of 0.38 lb/1000 ft\3\, 5200 ppm, or 6 g/m\3\ 
for R-1150.
6. What narrowed use limits is EPA finalizing?
    EPA is finalizing the following narrowed use limits for use of R-
1150 in VLTR:
    (1) Temperature range--R-1150 may only be used in equipment 
designed specifically to reach temperatures lower than -80 [deg]C (-112 
[deg]F).
    (2) The manufacturers of new very low temperature equipment must 
demonstrate that other alternatives are not technically feasible. They 
must document the results of their evaluation that showed the other 
alternatives to be not technically feasible and maintain that 
documentation in their files. This documentation, which does not need 
to be submitted to EPA unless requested to demonstrate compliance, 
``shall include descriptions of substitutes examined and rejected, 
processes or products in which the substitute is needed, reason for 
rejection of other alternatives, e.g., performance, technical or safety 
standards, and the anticipated date other substitutes will be available 
and projected time for switching to other available substitutes.'' (40 
CFR 82.180(b)(3)).
7. Why is EPA finalizing these specific narrowed use limits?
    The boiling point (b.p.) of a refrigerant determines the coldest 
temperature it can reach within its refrigerating capabilities. R-1150 
has a b.p. of -104 [deg]C, allowing it to refrigerate as cold as -104 
[deg]C. There are a limited number of refrigerants that are capable of 
reaching temperatures below -80 [deg]C, such as the ODSs CFC-13 (b.p., 
-81.4 [deg]C) and R-503 (b.p., -88.9 [deg]C), and among the acceptable 
refrigerants in this end-use, ethane (b.p., -88.3 [deg]C) and the high 
GWP refrigerants HFC-23 (b.p., -84.4 [deg]C), R-508A (b.p., -87.4 
[deg]C) and R-508B (b.p., -87.4 [deg]C).\54\ Given the limited 
refrigerant options available for equipment designed to reach the sub -
80 [deg]C temperature range, EPA understands there is a need for 
listing R-1150. However, EPA believes that limiting the use of R-1150 
to VLTR equipment designed to reach temperatures lower than -80 [deg]C 
(-112 [deg]F) is necessary to mitigate local air quality concerns 
discussed in section II.F.3 that could occur with broad use, given the 
reactivity of VOC and its potential to contribute to ground-level ozone 
in areas like Los Angeles. If R-1150 were used without limitation 
across the refrigeration and AC sector, it could have significant 
impacts on local air quality. For equipment in this end-use designed to 
reach temperatures higher than -80 [deg]C (-112 [deg]F), other 
alternatives with lower reactivities are widely available, e.g., 
CO2, ethane, propane, and R-410A. There are sufficient 
refrigerant options available to fill the need in VLTR equipment 
designed to reach temperatures higher than -80 [deg]C (-112 [deg]F) 
without allowing the use of refrigerants as photochemically reactive as 
R-1150. By including narrowed use limits, EPA is only allowing the use 
of R-1150, a refrigerant with higher reactivity, when it is the only 
technically feasible option available.
---------------------------------------------------------------------------

    \54\ Engineering ToolBox, 2005. Refrigerants--Physical 
Properties. Available online at: https://www.engineeringtoolbox.com/refrigerants-d_902.html Accessed October 28, 2021.
---------------------------------------------------------------------------

8. What additional information is EPA including in this final listing?
    EPA is providing additional information related to this listing. 
Since this additional information is not part of the regulatory 
decision under SNAP, these statements are not binding for use of the 
substitute under the SNAP program. See section II.E.2 above for further 
discussion on what additional information EPA is including in this 
final listing. While the items listed are not legally binding under the 
SNAP program, EPA encourages users of substitutes to apply all 
statements in the ``Further Information'' column in their use of these 
substitutes as best practices for safer use.
9. How is EPA responding to comments on VLTR?
    No comments were received relating to the proposed listing of R-
1150 in VLTR. For the reasons explained above, EPA is finalizing this 
section of the rule as proposed.

G. Streaming and Total Flooding Fire Suppression--Listing of 2-bromo-
3,3,3 trifluoropropene (2-BTP) as Acceptable, Subject to Use 
Conditions, as a Streaming Agent in Non-Residential Applications and as 
a Total Flooding Agent in Normally Unoccupied Spaces Under 500 ft\3\

1. Background on Streaming and Total Flooding Fire Suppression
    The fire suppression and explosion protection end-uses addressed in 
this action are total flooding and streaming. Total flooding systems, 
which historically employed halon 1301 as a fire suppression agent, are 
used in both normally occupied and unoccupied areas. In the United 
States, approximately 90 percent of installed total flooding systems 
protect anticipated hazards from ordinary combustibles (i.e., Class A 
fires), while the remaining ten percent protect against applications 
involving flammable liquids and gases (i.e., Class B fires).\55\ It is 
also estimated that approximately 75 percent of total flooding systems 
protect electronics (e.g., computers, telecommunications, process 
control areas), while the remaining 25 percent protect other 
applications, primarily in civil aviation (e.g., engine nacelles/
auxiliary power units, cargo compartments, lavatory trash receptacles), 
military weapons systems (e.g., combat vehicles, machinery spaces on 
ships, aircraft engines and tanks), oil/gas and manufacturing 
industries (e.g., gas/oil pumping, compressor stations), and maritime 
(e.g., machinery space, cargo pump rooms). Streaming applications, 
which have historically used halon 1211 as an extinguishing agent, 
include portable fire extinguishers designed to protect against 
specific hazards.
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    \55\ Wickham, 2002. Status of Industry Efforts to Replace Halon 
Fire Extinguishing Agents. March 2002.
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2. What is EPA's final listing decision for 2-BTP?
    As proposed, EPA is finalizing listing 2-BTP as acceptable, subject 
to use conditions. The use conditions are for use in normally 
unoccupied spaces under 500 ft\3\ in total flooding fire suppression 
systems, and as a streaming agent for use in non-residential 
applications, except for commercial home office and personal 
watercraft. EPA received one comment on the proposed listing of 2-BTP, 
and the commenter supported finalizing the rule as proposed. 2-BTP was 
previously listed as acceptable, subject to use conditions, for use in 
engine nacelles and auxiliary power units on aircraft in total flooding 
fire suppression systems and for use in aircraft as a streaming agent 
(81 FR 86778, December 1, 2016).
    The redacted submission and supporting documentation for 2-BTP are 
provided in the docket for this proposed rule (EPA-HQ-OAR-2021-0836) at 
https://www.regulations.gov. EPA performed assessments to examine the 
health and environmental risks of this substitute during equipment 
production operations and the filling of

[[Page 26408]]

fire extinguishers as well as in the case of an inadvertent discharge 
of the system during maintenance activities on the fire extinguishing 
system. These assessments are available in the docket for this 
rule.56 57
---------------------------------------------------------------------------

    \56\ ICF, 2022q. Risk Screen on Substitutes in Total Flooding 
Systems in Normally Unoccupied Spaces. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
    \57\ ICF, 2022r. Risk Screen on Substitutes as Streaming Agents 
in Non-Residential Applications. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
---------------------------------------------------------------------------

3. What is 2-BTP and how does it compare to other fire suppressants in 
the same end-uses?
a. Total Flooding
    Environmental information: 2-BTP has an ODP of 0.0028 
58 59 60 and a GWP of 0.23-0.26.\61\ 2-BTP is considered a 
VOC and is not excluded from EPA's regulatory definition of VOC (see 40 
CFR 51.100(s)) for the purpose of addressing the development of SIPs to 
attain and maintain the NAAQS.
---------------------------------------------------------------------------

    \58\ Patten, et al., 2011. OH, reaction rate constant, IR 
absorption spectrum, ozone depletion potentials and global warming 
potentials of 2-bromo-3,3,3-trifluoropropene, J. Geophys. Res., 116 
(D24), D24307, doi: 10.1029/2011JD016518, 2011.
    \59\ Orkin, V. L. 2004. Photochemical Properties of 2-bromo-
3,3,3-trifluoropropene and semi-empirical kinetic estimates of its 
Global Impacts on the Atmosphere. Prepared by the National Institute 
of Standards and Technology Physical and Chemical Properties 
Division for American Pacific Corporation. July 2004.
    \60\ The ODP in this rulemaking remains as it was originally 
listed by SNAP (see 81 FR 86778).
    \61\ Patten et al., 2012. Correction to ``OH reaction rate 
constant, IR absorption spectrum, ozone depletion potentials and 
global warming potentials of 2-bromo-3,3,3-trifluoropropene,'' J. 
Geophys. Res., 117, D22301, doi:10.1029/2012JD019051.
---------------------------------------------------------------------------

    Flammability information: 2-BTP is non-flammable.
    Toxicity and exposure data: EPA assessed potential health risks 
from exposure to the proposed substitute as a total flooding agent in 
normally unoccupied spaces up to 14.2 m\3\ (500 ft\3\) during 
manufacture, installation, and servicing of 2-BTP total flooding 
systems, consistent with the use description provided by the submitter. 
According to the SDS, exposure to 2-BTP following a discharge may be 
hazardous if inhalation, skin contact, or eye contact with the proposed 
substitute occurs at sufficiently high levels. However, the most likely 
pathway of exposure is through inhalation, which may cause central 
nervous system effects, such as dizziness, confusion, physical 
incoordination, drowsiness, anesthesia, or unconsciousness. The 
cardiotoxic Lowest Observed Adverse Effect Level (LOAEL) for this agent 
is 1.0 percent (10,000 ppm), at which level exposure may cause 
increased sensitivity of the heart to adrenaline, which might cause 
irregular heartbeats and possibly ventricular fibrillation or death.
    2-BTP vapors may reduce oxygen available for breathing, causing 
asphyxiation in high concentrations. Such vapors pose a potential 
hazard if large volumes are trapped in enclosed or low places. In 
addition, as noted above, if person(s) are exposed to high 
concentrations, the person(s) may experience central nervous system 
effects, such as drowsiness and dizziness, which may result in the 
person(s) not realizing that he/she is suffocating. These health 
effects after exposure are similar for other common fire suppressants.
    To assess potential health risks from exposure to the proposed 
substitute for personnel during manufacturing, EPA developed an AEL of 
2 ppm for 2-BTP based on review of available toxicity studies.\62\ The 
AEL represents the maximum 8-hour TWA at which personnel in an 
occupational environment can be exposed regularly without adverse 
effects. The estimated exposure values provided by the submitter are 
greater than the occupational AEL. To effectively mitigate potential 
occupational exposure and maintain average exposure levels below the 
occupational AEL of 2 ppm, the manufacturing space should be equipped 
with specialized engineering controls and well ventilated with a local 
exhaust system and low-lying source ventilation. The sampling data 
provided by the submitter demonstrate that local exhaust ventilation 
greatly reduces exposure concentration inside the fill booth and in the 
filling area.
---------------------------------------------------------------------------

    \62\ ICF, 2022r. Risk Screen on Substitutes in Total Flooding 
Systems in Normally Unoccupied Spaces. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
---------------------------------------------------------------------------

    Exposure to the substitute is not likely during installation or 
servicing of 2-BTP total flooding systems for normally unoccupied 
spaces. The risk of accidental activation of the fire extinguishing 
system while personnel are present near the protected space is highly 
unlikely if proper procedures are followed. Proper instructions on 
system installation and servicing included in manuals for the 2-BTP 
systems should be adhered to. In the case of accidental release, 
engineering controls in accordance with the National Fire Protection 
Association (NFPA) 2001 Standard on Clean Agent Fire Extinguishing 
Systems to limit personnel exposure to discharges should be employed 
with 2-BTP systems.
    EPA provides additional information on safe use of this substitute 
for establishments manufacturing, installing and maintaining equipment 
using this agent in the ``Further Information'' column of the 
regulatory listing. EPA recommends that a discharge time delay of 30 to 
60 seconds is programmed in accordance with the NFPA 2001 standard. 
Although exposure is highly unlikely during installation and 
maintenance activities, exposure is possible upon reentry into a space 
after a system has been discharged. In the event of an accidental 
release, the space should be adequately ventilated. EPA recommends that 
personnel wear protective clothing, goggles, gloves, and particulate-
removing respirators with National Institute for Occupational Safety 
and Health (NIOSH) type N95 or better filters while performing 
installation or maintenance, and a self-contained breathing apparatus 
(SCBA) while performing clean-up activities to reduce the risk of 
exposure. Since this additional information is not part of the 
regulatory decision under SNAP, these statements are not binding for 
use of the substitute under the SNAP program. While the items listed 
are not legally binding under the SNAP program, EPA encourages users of 
substitutes to apply all statements in the ``Further Information'' 
column in their use of this substitute as best practices for safer use.
    2-BTP is not expected to cause a significant risk to human health 
in the general population when used in total flooding systems in 
normally unoccupied areas. The use in spaces under 500 ft\3\ requires a 
smaller amount of fire suppressant, reducing potential exposures to 
workers and the general public and reducing potential toxicity risks. 
Disposal of 2-BTP total flooding systems is subject to local, State, 
and Federal regulations, which ensure that 2-BTP and water contaminated 
with 2-BTP are not to be dumped into sewers, on the ground, or into any 
body of water, but rather taken to a wastewater treatment facility or 
disposed of properly. 2-BTP is not considered to be hazardous waste 
under EPA regulations implementing RCRA at 40 CFR part 261.
    Comparison to other fire suppressants: 2-BTP has an ODP of 0.0028, 
comparable to or lower than other acceptable substitutes in this end-
use, with ODPs ranging from zero to 0.048. 2-BTP has a GWP of 0.23-0.26 
that is lower than or comparable to that of other acceptable 
substitutes for total flooding agents, with GWPs that range from about 
zero to 22,800.\63\ 2-BTP is

[[Page 26409]]

considered a VOC and is not excluded from EPA's regulatory definition 
of VOC (see 40 CFR 51.100(s)) for the purpose of addressing the 
development of SIPs to attain and maintain the NAAQS. Other acceptable 
fire suppression agents currently in use in this end-use are also VOC 
(e.g., C6-perfluoroketone), and 2-BTP is anticipated to pose 
no greater risk than other alternatives listed as acceptable in this 
end-use. Emissions of 2-BTP should be controlled by adhering to 
standard industry practices. Toxicity risks can be minimized by use 
consistent with the NFPA 2001 standard, recommendations in the SDS, and 
other safety precautions common in the fire suppression industry. The 
potential toxicity risks due to inhalation exposure are common to many 
total flooding agents, including those already listed as acceptable 
under SNAP for this same end-use. 2-BTP post-activation products are 
nonflammable, as are all other available total flooding agents.
---------------------------------------------------------------------------

    \63\ For SF6, the substitute with the highest GWP, 
the SNAP listing finds SF6 as ``acceptable subject to 
narrowed use limits.''
---------------------------------------------------------------------------

    EPA is finalizing listing 2-BTP as acceptable, subject to use 
conditions, as a total flooding agent for use in normally unoccupied 
spaces under 500 ft\3\ because the overall environmental and human 
health risk posed by the substitute is lower than or comparable to the 
overall risk posed by other alternatives listed as acceptable in the 
same end-use.
b. Streaming Uses
    Environmental information: The environmental information for this 
substitute is set forth in the ``Environmental information'' section in 
listing II.G.3.a above.
    Flammability information: 2-BTP is non-flammable.
    Toxicity and exposure data: Toxicity and personal protective 
equipment (PPE) information is described above under total flooding 
applications. EPA evaluated occupational and general population 
exposure at manufacture and at end-use to ensure that the use of 2-BTP 
as a streaming agent will not pose unacceptable risks to workers or the 
general public. For the occupational exposure assessment, EPA has 
evaluated the risks associated with potential exposures to 2-BTP during 
equipment production operations and the filling of fire extinguishers 
as well as in the case of an inadvertent discharge of the fire 
extinguisher during maintenance activities.
    2-BTP is not expected to pose a risk to workers during manufacture 
of 2-BTP fire extinguishers when the engineering controls and PPE 
requirements as referenced in the SDS for this substitute are followed. 
The potential health risks from exposure to the substitute for 
personnel during manufacturing is described above under total flooding 
applications.
    EPA also assessed potential end-use exposure scenarios at 7.5-
minute and 15-minute TWA exposures for 2-BTP following potential 
release of agent from the handheld extinguisher in confined spaces 
(e.g., electronics and server rooms).\64\ These exposures were then 
compared with the cardiotoxic LOAEL for 2-BTP. All but one modeled 7.5-
minute and 15-minute exposures for varying ventilation rates were lower 
than the LOAEL of 10,000 ppm for 2-BTP. The estimated exposures were 
derived using conservative assumptions (i.e., no mechanical 
ventilation) and represent a worst-case scenario with a low probability 
of occurrence. Because anticipated exposures could exceed the exposure 
limit for 2-BTP, EPA recommends that standard safety techniques to 
ensure safety during the use of 2-BTP fire extinguishers be followed in 
non-residential locations. 2-BTP handheld extinguishers should follow 
required minimum room volumes established by UL 2129, Halocarbon Clean 
Agent Fire Extinguishers,\65\ when discharged into a confined space. 
This standard prohibits the exceedance of the cardiotoxic LOAEL for any 
fire suppressant (i.e., 10,000 ppm or 1.0% for 2-BTP). Therefore, per 
UL 2129, a warning label for 2-BTP extinguishers will mitigate use in 
confined spaces. Based on the above results, 2-BTP is not expected to 
pose significant risk to end users when used as a streaming fire 
extinguishing agent in non-residential applications, except for 
commercial home office and personal watercraft. EPA provides additional 
information on safe use of this substitute for establishments 
manufacturing, installing and maintaining equipment using this agent in 
the ``Further Information'' column of the regulatory listing. Since 
this additional information is not part of the regulatory decision 
under SNAP, these statements are not binding for use of the substitute 
under the SNAP program. While the items listed are not legally binding 
under the SNAP program, EPA encourages users of substitutes to apply 
all statements in the ``Further Information'' column in their use of 
this substitute as best practices for safer use.
---------------------------------------------------------------------------

    \64\ ICF, 2022r. Risk Screen on Substitutes as Streaming Agents 
in Non-Residential Applications. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
    \65\ UL, 2017. Standard 2129--Halocarbon Clean Agent Fire 
Extinguishers. Edition 3. This document is accessible at: https://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=32182.
---------------------------------------------------------------------------

    Comparison to other fire suppressants: 2-BTP has an ODP of 0.0028, 
comparable to other listed substitutes in this end-use, with ODPs 
ranging from zero to 0.022. 2-BTP has a GWP of 0.23-0.26, which for 
streaming agents is lower than or comparable to that of other 
acceptable substitutes, with GWPs that range from about zero to 9,810. 
2-BTP is considered a VOC and is not excluded from EPA's regulatory 
definition of VOC (see 40 CFR 51.100(s)) for the purpose of addressing 
the development of SIPs to attain and maintain the NAAQS. Other 
acceptable fire suppression agents currently in use in this end-use are 
also VOC (e.g., C6-perfluoroketone), and 2-BTP is 
anticipated to pose no greater risk than other alternatives listed as 
acceptable in this end-use. Toxicity risks can be minimized by use 
consistent with the NFPA 10 Standard for Portable Fire Extinguishers, 
recommendations in the SDS, and other safety precautions common in the 
fire suppression industry.
    EPA is finalizing listing 2-BTP as acceptable, subject to use 
conditions, as a streaming agent for use in non-residential 
applications, except for commercial home office and personal 
watercraft, because the overall environmental and human health risk 
posed by the substitute is lower than or comparable to the overall risk 
posed by other alternatives listed as acceptable in the same end-use.
4. What use conditions is EPA finalizing?
    EPA is finalizing listing 2-BTP as acceptable, subject to use 
conditions. The use conditions are for use in normally unoccupied 
spaces under 500 ft\3\ in total flooding fire suppression systems, and 
as a streaming agent for use in non-residential applications, except 
for commercial home offices and personal watercraft.
5. Why is EPA finalizing these specific use conditions?
    EPA is finalizing listing 2-BTP as acceptable, subject to use 
conditions, for use only in normally unoccupied spaces under 500 ft\3\ 
in total flooding fire suppression systems. These space limitations are 
consistent with additional information submitted to EPA. The 
limitations correspond to use in small, enclosed spaces, such as an 
electrical closet. Such spaces would require a smaller amount of fire 
suppressant, reducing potential exposures to workers and the general 
public and reducing potential toxicity risks.
    Additionally, EPA is finalizing listing 2-BTP as acceptable subject 
to use conditions as a streaming agent for use

[[Page 26410]]

in non-residential applications, except for commercial home office and 
personal watercraft. The definition of ``residential use'' in the SNAP 
regulations at 40 CFR 82.172 is use by a private individual of a 
chemical substance or any product containing the chemical substance in 
or around a permanent or temporary household, during recreation, or for 
any personal use or enjoyment. Use within a household for commercial or 
medical applications is not included in this definition, nor is use in 
automobiles, watercraft, or aircraft. Use in a commercial home office 
or in personal watercraft could result in exposure to members of the 
general public, including sensitive individuals such as children or the 
elderly. In addition, air exchange is often lower in a commercial home 
office or a personal watercraft than in industrial or other commercial 
applications, potentially resulting in higher exposure levels than in 
those other non-residential applications. Because of the more sensitive 
populations and potentially higher exposures associated with those 
applications, EPA is finalizing listing 2-BTP for use in non-
residential applications other than commercial home office and personal 
watercraft.
6. How is EPA responding to comments on 2-BTP?
    EPA received one comment on the 2-BTP section of the proposed rule. 
The commenter supported finalizing the rule as proposed.
    Comment: American Pacific, the manufacturer of 2-BTP, indicated 
they ``[s]upport [the proposed rule] findings and conclusions with 
respect to the 2-BTP clean fire extinguishant.''
    Response: EPA acknowledges the support for this proposed listing, 
and for the reasons discussed above, we are finalizing this listing as 
proposed.

H. Total Flooding Fire Suppression--Listing of EXXFIRE [supreg] as 
Acceptable, Subject to Use Conditions, for Use in Normally Unoccupied 
Spaces

1. What is EPA's final listing decision for EXXFIRE [supreg]?
    As proposed, EPA is finalizing listing EXXFIRE [supreg] as 
acceptable, subject to use conditions, for use in total flooding fire 
suppression systems in normally unoccupied spaces. EPA received no 
comments relating to the proposed listing of EXXFIRE [supreg]. Prior to 
activation, the EXXFIRE [supreg] formulation is in solid form and 
contained within a hermetically sealed steel container. Upon detection 
of a fire, nitrogen gas is released from the unit. The nitrogen gas 
dilutes the oxygen level within the enclosure, and consequently 
suppresses the fire. After activation, only gas components exit the 
casing. All solid products remain inside the casing before, during and 
after activation. Use of this agent should be in accordance with the 
safety guidelines in the latest edition of the NFPA 2001 standard.
    The redacted submission and supporting documentation for EXXFIRE 
[supreg] are provided in the docket for this proposed rule (EPA-HQ-OAR-
2021-0836) at https://www.regulations.gov. EPA performed an assessment 
to examine the health and environmental risks of each of this 
substitute. This assessment is available in the docket for this 
rule.\66\
---------------------------------------------------------------------------

    \66\ ICF, 2022s. Risk Screen on Substitutes in Total Flooding 
Systems in Normally Unoccupied Spaces; Substitute: EXXFIRE [supreg].
---------------------------------------------------------------------------

2. What is EXXFIRE [supreg] and how does it compare to other fire 
suppressants in the same end-use?
    Environmental information: According to the submitter, the active 
ingredients for this technology are nonvolatile solids before 
activation so the ODP, atmospheric lifetime, and GWP are all zero. The 
gaseous post-activation products that are released upon activation of 
the fire suppressant with GWPs are carbon monoxide (CO), 
CO2, and various hydrocarbons with GWPs ranging from less 
than one to 25; however, these compounds are present in trace amounts, 
together making up less than 0.5 percent of the total weight of the 
post-activation products. The majority of the post-activation 
constituents of EXXFIRE [supreg] are either not organic (e.g., 
nitrogen, oxygen, water, hydrogen) or are excluded from EPA's 
regulatory definition of VOC (see 40 CFR 51.100(s)), for the purpose of 
addressing the development of SIPs to attain and maintain the NAAQS. 
Some constituents of EXXFIRE [supreg] are considered VOC and are not 
excluded from EPA's regulatory definition of VOC (see 40 CFR 
51.100(s)), including a variety of hydrocarbons; however, these 
compounds are present in trace amounts.
    Flammability information: EXXFIRE [supreg] post-activation products 
are non-flammable, except for certain hydrocarbons that are present in 
trace amounts.
    Toxicity and exposure data: EPA assessed potential health risks 
from exposure. Most post-activation products for EXXFIRE [supreg] are 
not expected to result in adverse health effects; however, due to the 
potential presence of lithium fluoride, which is acutely toxic upon 
inhalation or ingestion and can cause serious skin, eye, and 
respiratory tract irritation, the use of this system is only 
recommended for use in normally unoccupied spaces. Although expected to 
be maintained inside the generator, the potential presence of lithium 
fluoride in the post-activation particulate products, justifies the 
necessity for personnel to wear proper PPE (i.e., particulate-removing 
respirator with NIOSH type N95 or better filters) upon reentry into the 
space following a discharge of the system to mitigate those risks. The 
submitter indicates that the proposed substitute can reduce oxygen 
levels to 10 to 12 percent, which can cause a potential asphyxiation 
hazard.
    EPA evaluated occupational and general population exposure at 
manufacture of EXXFIRE [supreg] systems and at end use to ensure that 
the use of EXXFIRE [supreg] will not pose unacceptable risks to workers 
or the general public. Exposure is possible upon reentry into a space 
after a system has been discharged. Protective gloves, tightly sealed 
goggles, protective work clothing, and particulate-removing respirators 
should be worn for installation and servicing activities, to protect 
workers in any event of potential discharge of the substitute, 
accidental or otherwise. Filling or servicing operations should be 
performed in well-ventilated areas. Toxicity risks can be minimized by 
use consistent with the NFPA 2001 standard, recommendations in the SDS, 
and other safety precautions common in the fire suppression industry. 
EPA provides additional information on safe use of this substitute for 
establishments manufacturing, installing and maintaining equipment 
using this agent in the ``Further Information'' column of the 
regulatory listing. Since this additional information is not part of 
the regulatory decision under SNAP, these statements are not binding 
for use of the substitute under the SNAP program. While the items 
listed are not legally binding under the SNAP program, EPA encourages 
users of substitutes to apply all statements in the ``Further 
Information'' column in their use of this substitute as best practices 
for safer use.
    Comparison to other fire suppressants: EXXFIRE [supreg] has an ODP 
of zero, comparable to other listed substitutes in this end-use, with 
ODPs ranging from zero to 0.048. For total flooding agents, EXXFIRE 
[supreg] has a GWP of zero prior to activation (and one to 25 for 
certain post-activation products present in trace amounts), which is 
comparable to or lower than that of other acceptable substitutes, such 
as HFC-227ea and other substitutes with

[[Page 26411]]

GWPs up to 22,800.\67\ The majority, approximately 99.5 percent, of the 
post-activation constituents of EXXFIRE [supreg] are either not organic 
or are excluded from EPA's regulatory definition of VOC (see 40 CFR 
51.100(s)), for the purpose of addressing the development of SIPs to 
attain and maintain the NAAQS. EXXFIRE [supreg] is anticipated to pose 
no greater risk than other alternatives listed as acceptable in this 
end-use. Toxicity risks can be minimized by use consistent with the 
NFPA 2001 standard, recommendations in the SDS, and other safety 
precautions common in the fire suppression industry. The potential 
toxicity risks due to inhalation exposure are common to many total 
flooding agents, including those already listed as acceptable under 
SNAP for this same end-use. EXXFIRE [supreg]'s post-activation products 
are nonflammable, as are all other available total flooding agents.
---------------------------------------------------------------------------

    \67\ For SF6, the substitute with the highest GWP, 
the SNAP listing finds SF6 as ``acceptable subject to 
narrowed use limits.''
---------------------------------------------------------------------------

    EPA is finalizing listing EXXFIRE [supreg] as acceptable, subject 
to use conditions, in the end-use listed above because it does not pose 
greater overall environmental and human health risk than other 
available substitutes in the same end-use.
3. What use conditions is EPA finalizing and why?
    Consistent with the request by the submitter, and information we 
have available at this time for our review, the use condition requires 
that EXXFIRE [supreg] be used in total flooding fire suppression 
systems only in areas that are not normally occupied. EPA conducted 
this evaluation for use only in unoccupied spaces, and information was 
provided by the submitter in the SNAP application specific for this 
type of space based on EPA guidance.\68\ EPA needs additional 
information, such as additional toxicity test information, to issue a 
listing for normally occupied spaces, compared to a listing for 
normally unoccupied spaces. This is because of the greater risk that 
workers or members of the general public may be exposed if a fire 
suppressant is used in normally occupied spaces. In the absence of such 
information, as described in EPA's guidance, EPA issues listings for 
powdered aerosol fire suppressants as acceptable subject to use 
conditions for use in normally unoccupied spaces only.
---------------------------------------------------------------------------

    \68\ EPA, 2004. A Guide to Completing a Risk Screen: Collection 
and Use of Risk Screen Data. Fire Suppression Sector. April 2004.
---------------------------------------------------------------------------

4. How is EPA responding to comments on EXXFIRE [supreg]?
    No comments were received regarding EPA's proposed listing for 
EXXFIRE [supreg], and for the reasons explained above EPA is finalizing 
this listing as proposed.

I. Total Flooding Fire Suppression--Listing of Powdered Aerosol H 
(Pyroquench-[alpha] TM) as Acceptable, Subject to Use 
Conditions, for Use in Normally Unoccupied Spaces

1. What is EPA's final listing decision for Powdered Aerosol H?
    As proposed, EPA is finalizing listing Powdered Aerosol H, also 
known as Pyroquench-[alpha] TM, as acceptable, subject to 
use conditions, for use in total flooding fire suppression systems in 
normally unoccupied spaces. EPA received no comments relating to the 
proposed listing of Powdered Aerosol H. Prior to activation, the 
Powdered Aerosol H formulation is contained as a solid disk of 
chemicals in insulated and dual-sealed casings. In response to heat and 
lack of oxygen, the formulation undergoes a chemical reaction; once the 
Powdered Aerosol H system is activated, it generates and discharges a 
homogenous mixture of gas and particulates into a space containing a 
fire hazard or directly on the hazard itself, extinguishing the fire. 
In the ``Further Information'' column of the tables at the end of this 
document, we state that use of this agent should be in accordance with 
the safety guidelines in the latest edition of the NFPA 2010 Standard 
for Fixed Aerosol Fire Extinguishing Systems.
    The redacted submission and supporting documentation for Powdered 
Aerosol H are provided in the docket for this final rule (EPA-HQ-OAR-
2021-0836) at https://www.regulations.gov. EPA performed an assessment 
to examine the health and environmental risks of each of this 
substitute. This assessment is available in the docket for this final 
rule.69 70
---------------------------------------------------------------------------

    \69\ ICF, 2022t. Risk Screen on Substitutes in Total Flooding 
Systems in Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
    \70\ ICF, 2023b. Risk Screen on Substitutes in Total Flooding 
Systems in Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
---------------------------------------------------------------------------

2. What is Powdered Aerosol H and how does it compare to other fire 
suppressants in the same end-use?
    Environmental information: According to the submitter, the active 
ingredients for this technology are nonvolatile solids before 
activation so the ODP, atmospheric lifetime, and GWP are all zero. The 
gaseous post-activation products that are released upon activation of 
the fire suppressant with GWPs are nitrogen dioxide (NO2) 
and CO2, with GWPs of close to zero 71 72 and 
one, respectively. The post-activation constituents of Powdered Aerosol 
H are excluded from EPA's regulatory definition of VOC (see 40 CFR 
51.100(s)), for the purpose of addressing the development of SIPs to 
attain and maintain the NAAQS.
---------------------------------------------------------------------------

    \71\ Myhre, et.al., 2013: Anthropogenic and Natural Radiative 
Forcing. In: Climate Change 2013: The Physical Science Basis. 
Contribution of Working Group I to the Fifth Assessment Report of 
the Intergovernmental Panel on Climate Change [Stocker, T.F., D. 
Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, 
Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, 
Cambridge, United Kingdom and New York, NY, USA. Available online 
at: https://www.ipcc.ch/report/ar5/wg1/.
    \72\ In the proposal for this rule, EPA incorrectly noted the 
GWP for NO2 as 120. EPA is correcting the GWP and 
citation in this final rule. This correction does not change EPA's 
listing of acceptable, subject to use conditions, as set forth in 
the rule, for use of Powdered Aerosol H in fire protection.
---------------------------------------------------------------------------

    Flammability information: Powdered Aerosol H post-activation 
products are non-flammable.
    Toxicity and exposure data: EPA assessed potential health risks 
from exposure to the proposed substitute as a total flooding agent in 
normally unoccupied spaces. Because the pre-activation components of 
the fire suppressant are prepared in tablets that are non-reactive and 
do not crumble or flake, there is no concern regarding inhalation or 
ingestion of the pre-activation compounds. The discharge of the 
powdered aerosol after activation results in temporary reduced 
visibility in the protected space due to the uniform distribution of 
the particulate generated and may cause ocular, dermal, and respiratory 
irritation. EPA recommends that workers not enter the space following 
discharge until all particles have settled and the gases released by 
the total flooding system have dissipated. Use according to the NFPA 
2010 Standard will reduce any safety risks due to reduced visibility. 
The use of proper PPE, such as protective clothing, gloves, goggles, 
and particulate-removing respirators, during manufacturing, at 
installation, maintenance, and clean-up, minimizes personnel exposure 
from inhalation of the substitute. EPA provides additional information 
on safe use of this substitute for establishments manufacturing, 
installing and maintaining equipment using this agent in the ``Further 
Information'' column of the regulatory listing. Since this additional 
information is not part of the regulatory decision under SNAP, these

[[Page 26412]]

statements are not binding for use of the substitute under the SNAP 
program. While the items listed are not legally binding under the SNAP 
program, EPA encourages users of substitutes to apply all statements in 
the ``Further Information'' column in their use of this substitute as 
best practices for safer use.
    EPA expects that procedures identified in the SDS for Powdered 
Aerosol H and good manufacturing practices will be adhered to, and that 
the appropriate safety and personal PPE consistent with OSHA guidelines 
will be used during installation, servicing, post-discharge clean-up 
and disposal of total flooding systems using Powdered Aerosol H. The 
manufacturer guidance upon installation of the system provides the 
appropriate time after which workers may re-enter the area for disposal 
to allow the maximum settling of all particulates.
    Comparison to other fire suppressants: The post-activation products 
of Powdered Aerosol H have an ODP of zero, comparable to or lower than 
other listed substitutes in this end-use, with ODPs ranging from zero 
to 0.048. For total flooding agents, Powdered Aerosol H's GWP of zero 
prior to activation (and close to zero and one for certain post-
activation products) is comparable to or lower than that of other 
acceptable substitutes, such as HFC-227ea and other substitutes with 
GWPs up to 22,800.\73\ Other acceptable substitutes in this end-use 
have comparable GWPs ranging from zero to one, such as water, inert 
gases, and other powdered aerosol fire suppressants. Toxicity risks can 
be minimized by use consistent with the NFPA 2010 standard, 
recommendations in the SDS, and other safety precautions common in the 
fire suppression industry. The potential toxicity risks due to 
inhalation exposure are common to many total flooding agents, including 
those already listed as acceptable under SNAP for this same end-use. 
Powdered Aerosol H's post-activation products are nonflammable, as are 
all other available total flooding agents.
---------------------------------------------------------------------------

    \73\ For SF6, the substitute with the highest GWP, 
the SNAP listing finds SF6 as ``acceptable subject to 
narrowed use limits.''
---------------------------------------------------------------------------

    EPA is finalizing listing Powdered Aerosol H as acceptable, subject 
to use conditions, in the end-use listed above because it does not pose 
greater overall environmental and human health risk than other 
available substitutes in the same end-use.
3. What use conditions is EPA finalizing and why?
    Consistent with the submitter's request, and information we have 
available at this time for our review, EPA finalizes the use condition 
that Powdered Aerosol H be used in total flooding fire suppression 
systems only in areas that are not normally occupied. EPA conducted 
this evaluation for use only in unoccupied spaces, and information was 
provided by the submitter in the SNAP application specific for this 
type of space based on EPA guidance.\74\ EPA needs additional 
information, such as additional toxicity test information, to issue a 
listing for normally occupied spaces, compared to a listing for 
normally unoccupied spaces. This is because of the greater risk that 
workers or members of the general public may be exposed to if a fire 
suppressant is used in normally occupied spaces. In the absence of such 
information, as described in EPA's guidance, EPA issues listings for 
powdered aerosol fire suppressants as acceptable subject to use 
conditions for use in normally unoccupied spaces only.
---------------------------------------------------------------------------

    \74\ EPA, 2004. A Guide to Completing a Risk Screen: Collection 
and Use of Risk Screen Data. Fire Suppression Sector. April, 2004.
---------------------------------------------------------------------------

4. How is EPA responding to comments on Powdered Aerosol H?
    No comments were received regarding EPA's proposed listing for 
Powdered Aerosol H, and for the reasons discussed above, EPA is 
finalizing this section of the rulemaking as proposed.

J. How is EPA responding to other comments?

    Comment: Several commenters (AHRI, the Alliance, AHAM, Carrier, 
EIA, Brigett Griffin, LG Electronics, Chemours, and Trane) noted 
general support for this rulemaking. Additionally, the Alliance and 
AHAM stressed a desire for the Agency to issue a final rule in a timely 
manner to ensure that lower GWP alternatives are available. Trane noted 
their support for a transition to lower flammability ``A2L'' 
refrigerants.
    Response: EPA acknowledges the commenters' support of the listings 
in this rulemaking. The Agency acknowledges Trane's support for listing 
A2L refrigerants. EPA is finalizing many listing decisions as proposed 
and is finalizing other listing decisions with relatively minor changes 
that address and incorporate information provided in comments as 
described throughout the preamble above.
    Comment: EIA commented on the GWP of HFC-32 and noted that 
refrigerants like HFC-32 have lower GWPs than the chemicals they 
replace and are near-term solutions which help facilitate the reduction 
in demand for HFCs under the American Innovation and Manufacturing 
(AIM) Act of 2020. EIA urged that EPA should consider restricting these 
refrigerants in the future, once additional ultra-low GWP refrigerants 
become more widely adopted.
    Response: EPA acknowledges EIA's concern for the GWPs of various 
refrigerants and recognition that new alternatives will be more widely 
adopted in the future. EPA plans to continue to review the GWPs of 
substitutes consistent with the SNAP program criteria. EIA's comment on 
the AIM Act is beyond the scope of this action.
    Comment: Diversified CPC International stated that EPA should 
consider listing the ASHRAE A3 refrigerants R-290, R-600, R-600a, R-
601a, R-1270, and blends (i.e., propane, butane, isobutane, isopentane, 
propylene, and blends) as acceptable to align with UL 60335-2-89, 2nd 
Edition and UL 60335-2-40, 3rd Edition. Additionally, Diversified CPC 
International and EIA stated that they hoped EPA will prioritize 
adoption of revised use conditions for refrigeration equipment in a 
future rule to take into account UL 60335-2-89, 2nd Edition, which 
would include expanded charge limits for hydrocarbons up to 500 g in 
self-contained equipment. EIA also stated that modernizing standards 
for commercial refrigeration will open a pathway for companies to 
significantly reduce climate impacts while maintaining safe systems. 
ATMOsphere urged that EPA consider the impending use of hydrocarbons in 
chillers, ACs and HPs and stated that such systems are becoming widely 
used in Europe.
    Response: EPA acknowledges these comments expressing support for 
hydrocarbons in the refrigeration and AC sector. EPA did not propose to 
revise the current use conditions for R-290 or the hydrocarbon blend R-
441A for use in self-contained room ACs and HPs. The Agency also did 
not propose to list R-290, R-600, R-600a, R-601a, R-1270, and blends 
for use in other end-uses. Therefore, these comments are beyond the 
scope of this rulemaking. The Agency may consider proposing additional 
listings, including listings for hydrocarbons and other lower-GWP 
refrigerants in commercial refrigeration in future rulemakings, in 
addition to updating use conditions for existing hydrocarbon listings. 
EPA

[[Page 26413]]

acknowledges that in other countries, refrigerants used in chillers may 
differ from the United States. The Agency's review of substitutes 
relies on the SNAP program criteria and the conditions in the United 
States, not on whether a substitute is in use elsewhere.
    Comment: ATMOsphere urged the use of refrigerants such as 
hydrocarbons, CO2, and ammonia in split-system AC, household 
refrigerators, supermarket cases, HPs, HP water heaters, and chillers.
    Response: EPA acknowledges the increasing use of both fluorinated 
and non-fluorinated alternatives to ODS. In this action, EPA did not 
propose to list hydrocarbons, CO2, or ammonia and thus is 
not finalizing such a listing in this final rule. The Agency intends to 
consider proposing additional listings, including listings for non-
fluorinated alternatives, in future rulemakings.
    Comment: Savannah River Nuclear Solutions stated that EPA needs to 
exempt the flammable refrigerants identified as being exempt from the 
venting prohibition contained in 40 CFR 82.l54(a) from RCRA by adding 
language to 40 CFR 261.2 and/or 40 CFR 261.4. This commenter stated 
that the lack of exemption in 40 CFR 261.2 and/or 40 CFR 261.4 has 
resulted in confusion on EPA's position with respect to RCRA regulation 
of flammable refrigerants that are exempted under 40 CFR 82.154(a) from 
the venting prohibition. Savannah River Nuclear Solutions noted that 
the refrigerants in the end-uses described at Subpart G, Appendix R, 
Items l, 2, 5 and 6 in the July 28, 2022 NPRM are exempt from the 
venting prohibition contained in 40 CFR 82.l54(a) and in this text, 
there is no indication the recovery or disposal of these refrigerants 
in these end uses are hazardous waste under RCRA even when venting 
occurs in a non-household setting. This commenter cited from multiple 
rulemakings that exempted certain refrigerants from the venting 
prohibition under CAA section 608(c)(2).
    Response: EPA did not open for comment the listings 1 through 6 in 
appendix R to 40 CFR part 82, subpart G mentioned by the commenter. 
Rather, those entries were republished ``to bring the table in line 
with the Office of the Federal Register's general requirement for 
orderly codification by: adding entry numbers, replacing prohibited 
language, and properly formatting the footnotes.'' (87 FR at 45509; 
July 28, 2022). Similarly, EPA did not reopen the regulations at 40 CFR 
261.2 and 40 CFR 261.4 through the NPRM. For these reasons, EPA 
considers the comment to be outside of the scope of this rulemaking.
    In light of the commenter's statement about confusion regarding the 
RCRA regulation of flammable refrigerants that are exempted under 40 
CFR 82.154(a) from the venting prohibition, we note that we have 
already addressed the applicability of RCRA to spent refrigerants in a 
previous SNAP rule, which states, for example, that ``propane and other 
HCs being recovered, vented, released, or otherwise disposed of from 
commercial and industrial appliances are likely to be hazardous waste 
under RCRA (see 40 CFR parts 261 through 270).'' (See 81 FR at 86799-
86800, December 1, 2016, for additional information).
    Comment: ATMOsphere, EIA, and an anonymous member of the public 
commented on the atmospheric decomposition of HFC-134a and HFO-1234yf 
into trifluoroacetic acid (TFA). ATMOsphere stated that TFA is 
collecting in the environment, and EIA claimed that ``the presence of 
persistent fluorinated by-products of HFCs and HFOs is increasing in 
the environment,'' citing studies finding increasing levels of TFA in 
ice cores,\75\ rainwater,\76\ groundwater,\77\ and leaf samples.\78\ 
All three commenters expressed concern about the potential risks TFA 
might pose to human health and the environment. EIA asserted, ``it is 
reasonable to conduct a complete review of these chemicals rather than 
allow their continued proliferation,'' and suggested that EPA should 
evaluate the potential risks from TFA through future SNAP regulations.
---------------------------------------------------------------------------

    \75\ Chemical and Engineering News, May 1, 2020. ``CFC 
replacements are a source of persistent organic pollution in the 
Arctic.'' K. Bourzic. Available online at: https://cen.acs.org/environment/persistent-pollutants/CFC-replacements-source-persistent-organic/98/web/2020/05.
    \76\ Freeling et al., 2020. F. Freeling, D. Behringer, F. 
Heydel, M. Scheurer, T. Ternes, and K. N[ouml]dler. 
``Trifluoroacetate in Precipitation: Deriving a Benchmark Data Set'' 
Environ. Sci. Technol. 2020, 54, 18, 11210-11219. August 17, 2020. 
Available online at: https://pubs.acs.org/doi/10.1021/acs.est.0c02910.
    \77\ Zihan Zhai et al., 2015. Zihan Zhai, Jing Wu, Xia Hu, Li 
Li, Junyu Guo, Boya Zhang, Jianxin Hu, and Jianbo Zhang. ``A 17-fold 
increase of trifluoroacetic acid in landscape waters of Beijing, 
China during the last decade,'' Chemosphere. 2015 Jun; 129:110-7. 
doi: 10.1016/j.chemosphere.2014.09.033. Abstract available online at 
https://pubmed.ncbi.nlm.nih.gov/25262947/.
    \78\ Freeling et al., 2022. F. Freeling, M. Scheurer, J. 
Koschorreck, G. Hoffmann, T.A. Ternes, and K. N[ouml]dler. ``Levels 
and Temporal Trends of Trifluoroacetate (TFA) in Archived Plants: 
Evidence for Increasing Emissions of Gaseous TFA Precursors over the 
Last Decades,'' Environ. Sci. Technol. Lett. 2022, 9, 5, 400-405. 
April 18, 2022. Available online at: https://pubs.acs.org/doi/10.1021/acs.estlett.2c00164.
---------------------------------------------------------------------------

    Response: EPA appreciates the information provided by EIA on the 
atmospheric decomposition of HFO-1234yf to TFA. We note that several 
studies and reports provide further information about this topic. A 
2014 study by Kazil, et al. analyzed TFA deposition in the United 
States assuming 100 percent of all motor vehicle air conditioning 
(MVAC) systems use HFO-1234yf, which was the largest use of HFO-1234yf 
at that time.\79\ The results indicated that rainwater TFA 
concentrations, while varying strongly geographically, will on average 
be low compared to the levels at which toxic effects are observed in 
aquatic systems. Similarly low TFA concentrations were estimated for 
emissions of HFO-1234yf from Asia in a 2021 study by David, et al.\80\ 
The World Meteorological Organization also provided a summary of key 
information pertaining to TFA in their 2022 report to the Montreal 
Protocol.\81\ The report states:
---------------------------------------------------------------------------

    \79\ Kazil et al., 2014. ``Deposition and rainwater 
concentrations of trifluoroacetic acid in the United States from the 
use of HFO-1234yf'' J. Kazil, S. McKeen, S.-W. Kim, R. Ahmadov, G.A. 
Grell, R.K. Talukdar, A.R. Ravishankara. JGR Atmospheres. Volume 
119, Issue 24. December 27, 2014. Pages 14,059-14,079. October 31, 
2014. Available online at https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022058.
    \80\ David et al., 2021. ``Trifluoroacetic acid deposition from 
emissions of HFO-1234yf in India, China, and the Middle East,'' 
Volume 21, issue 19. Atmos. Chem. Phys., 21, 14833-14849, 2021. 
https://doi.org/10.5194/acp-21-14833-2021. Available online at 
ttps://acp.copernicus.org/articles/21/14833/2021/.
    \81\ World Meteorological Organization (WMO), 2022. Executive 
Summary. Scientific Assessment of Ozone Depletion: 2022, GAW Report 
No. 278, 56 pp.; WMO: Geneva, 2022. Available online at https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf.

    The formation in the atmosphere of trifluoroacetic acid (TFA) is 
expected to increase in the coming decades due to increased use of 
HFOs and HCFOs. TFA, a breakdown product of some HFCs, HCFCs, HFOs 
and HCFOs, is a persistent chemical with potential harmful effects 
on animals, plants, and humans. The concentration of TFA in 
rainwater and ocean water is, in general, significantly below known 
toxicity limits at present. Potential environmental impacts of TFA 
---------------------------------------------------------------------------
require future evaluation due to its persistence. (p. 14)

    Most TFA currently found in the environment resulting from 
decomposition of refrigerants likely derived from HFC-134a, which is 
being phased down and the use of which is anticipated to decrease in 
end-uses where safer alternatives are found acceptable under the SNAP 
program. EPA also notes that the modeling studies referenced generally 
assume a one-to-one substitution of HFO-1234yf for HFC-134a to be 
conservative;

[[Page 26414]]

however, none of the end-uses in this final rule where HFO-1234yf is 
being listed as acceptable are anticipated to cause a one-for-one 
transition from HFC-134a to HFO-1234yf. Any increase in TFA deposition 
due to this rule is expected to be less than the modeled increases in 
TFA from studies that found the levels of TFA in the environment 
remained, ``too small to be a risk to the environment over the next few 
decades.'' Use of HFO-1234yf and concerns about TFA in applications not 
addressed by this final rule are outside the scope of this rulemaking.
    There are ongoing evaluations of the potential risks of TFA 
exposure. In 2020, the Environmental Effects Assessment Panel (EEAP) to 
the Montreal Protocol released an update \82\ to its report on the 
environmental effects of stratospheric ozone depletion, UV radiation, 
and interactions with climate change, including the potential effects 
of TFA from ODS and their substitutes. That report noted that TFA ``has 
a no-observed-effect-concentration (NOEC) for aquatic species, which is 
typically >10,000 [mu]g/L,'' while ``analysis of 1187 samples of 
rainwater collected in eight locations across Germany in 2018-2019 
showed median and a precipitation-weighted mean concentration of TFA of 
0.210 [mu]g/L and 0.335 [mu]g/L, respectively,'' and ``another recent 
paper reported TFA . . . in precipitation in the low [mu]g/L range 
across 28 cities in mainland China.'' These studies and others led the 
EEAP to state, ``Trifluoroacetic acid continues to be found in the 
environment, including in remote regions, although not at 
concentrations likely to have adverse toxicological consequences.''
---------------------------------------------------------------------------

    \82\ EEAP, 2020. ``Environmental effects of stratospheric ozone 
depletion, UV radiation, and interactions with climate change: UNEP 
Environmental Effects Assessment Panel, Update 2020.'' Photochemical 
& Photobiological Sciences https://doi.org/10.1007/s43630-020-00001-x. Available online at: https://engineering.case.edu/centers/sdle/sites/engineering.case.edu.centers.sdle/files/neale_et_al._-_2021_-_environmental_effects_of_stratospheric_ozone_deple.pdf.
---------------------------------------------------------------------------

    In its 2021 Summary Update for Policymakers,\83\ the EEAP stated:
---------------------------------------------------------------------------

    \83\ EEAP, 2021. ``Summary Update 2021 for Policymakers'' UNEP 
Environmental Effects Assessment Panel. Available online at: https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.

    TFA likely has natural geochemical sources, is widely used in 
industry and research laboratories, and is a by-product of the 
synthesis and degradation of fluorinated and perfluorinated 
compounds (PFCs). . . . TFA has recently been found in 
precipitation, surface waters, and indoor dust in China . . ., 
although concentrations are below those considered toxic. No 
additional studies on the toxicity of TFA to organisms have been 
reported, but prior research has shown that this compound is not 
highly toxic to mammals and aquatic organisms, although some plants 
and algae may be sensitive. . . . At present, it is not possible to 
quantify the proportion of anthropogenic sources of TFA resulting 
from substances not falling under the purview of the Montreal 
Protocol, but available evidence indicates that this breakdown 
product is of minimal risk to human health. (p. 10; references in 
---------------------------------------------------------------------------
the text omitted here)

    In response to EIA's suggestion that EPA evaluate potential risks 
from TFA through future SNAP rules, EPA notes that it does consider 
ecotoxicity as a criterion when evaluating alternatives under SNAP's 
comparative risk framework, and the Agency has considered the potential 
impacts of TFA in past actions that found HFO-1234yf acceptable in 
certain end-uses. For example, EPA studied the potential generation of 
TFA when first listing neat (i.e., 100%, not in blends) HFO-1234yf as 
acceptable, subject to use conditions, in motor vehicle air 
conditioning. The myriad studies EPA referenced all concluded that the 
additional TFA from HFO-1234yf did not pose a significant additional 
risk, even if it were assumed to be used as the only refrigerant in all 
refrigeration and air conditioning equipment (76 FR 17492-17493, March 
29, 2011). The Agency intends to continue its approach to evaluating 
the potential risks from TFA in future SNAP regulations. Based on 
current information, EPA does not consider the overall risk to human 
health and the environment due to the listings in this final rule to be 
significantly greater than for other available or potentially available 
substitutes for the same uses.
    Comment: Three commenters (ATMOsphere, EIA, and an anonymous 
commenter) expressed concern about per- and poly-fluoroalkyl substances 
(PFAS). Commenters noted that under some definitions of PFAS, HFCs and 
HFOs discussed in this rule are considered PFAS, and two of the 
commenters suggested EPA should adopt a particular definition of PFAS. 
The commenters noted that some PFAS chemicals, e.g., perfluorooctanoic 
acid (PFOA) and perfluorooctane sulfonate (PFOS), present risks to 
human health and the environment.
    Response: EPA understands that currently, there is no single 
commonly agreed definition of PFAS, and whether or not HFCs or HFOs are 
classified as PFAS depends on the definition being used. EPA's PFAS 
roadmap, available at https://www.epa.gov/pfas, sets timelines for 
specific actions and outlines EPA's commitments to new policies to 
safeguard public health, protect the environment, and hold polluters 
accountable. This rule does not in any way establish a definition of 
PFAS, nor do the listing decisions depend on a specific definition. In 
evaluating alternatives using its comparative risk framework, SNAP 
already considers potential risks to human health and the environment. 
Regardless of what definition of PFAS is used, not all PFAS are the 
same in terms of toxicity or any other risk. Some PFAS have been shown 
to have extremely low toxicity, for example. If a chemical has been 
found to present lower overall risk to human health or the environment, 
it might be found acceptable under SNAP regardless of whether or not it 
falls under a particular definition of PFAS. Likewise, SNAP might not 
find a potential alternative acceptable if it presented greater overall 
risk, regardless of whether or not it falls under a particular 
definition of PFAS. As described in the risk screens for alternatives 
found in the docket for this rulemaking, potential risk to human health 
or the environment has been considered directly for each chemical, and 
the risks are not assumed to follow from a chemical falling into any 
particular category of substances.

III. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was 
therefore not submitted to the Office of Management and Budget (OMB) 
for review.

B. Paperwork Reduction Act (PRA)

    OMB has previously approved the information collection activities 
contained in the existing regulations and has assigned OMB control 
number 2060-0226. The approved Information Collection Request includes 
five types of respondent reporting and recordkeeping activities 
pursuant to SNAP regulations: submission of a SNAP petition, filing a 
Toxic Substances Control Act (TSCA)/SNAP Addendum, notification for 
test marketing activity, recordkeeping for substitutes acceptable 
subject to use restrictions, and recordkeeping for small volume uses. 
This action does not impose a new information collection burden under 
the PRA because the existing Information Collection Request already 
includes recordkeeping for substitutes acceptable subject to use 
restrictions--i.e., acceptable subject to

[[Page 26415]]

use conditions or acceptable subject to narrowed use limits.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, EPA concludes that the impact of concern for 
this rule is any significant adverse economic impact on small entities 
and that the agency is certifying that this rule will not have a 
significant economic impact on a substantial number of small entities 
because the rule has no net burden on the small entities subject to the 
rule. This action adds the additional options under SNAP of using HFC-
32, HFO-1234yf, R-452B, R-454A, R-454B, R-454C, R-1150, 2-BTP, EXXFIRE 
[supreg], and Powdered Aerosol H, in the specified end-uses, but does 
not mandate such use. Users who choose to avail themselves of this 
flexibility for R-1150 must make a reasonable effort to ascertain that 
other substitutes or alternatives are not technically feasible and must 
document and keep records of the results of such investigations. 
Because equipment for HFC-32, HFO-1234yf, R-452B, R-454A, R-454B, and 
R-454C is not manufactured yet in the U.S. for the chillers and 
residential dehumidifiers end-uses, no change in business practice is 
required to meet the use conditions, resulting in no adverse impact 
compared with the absence of this rule. Similarly, R-1150, 2-BTP, 
EXXFIRE [supreg], and Powdered Aerosol H are listed as acceptable with 
use conditions consistent with industry standards and with the intended 
uses described by the submitters, also requiring no change in business 
practices and resulting in no adverse impact compared with the absence 
of this rule. The new use conditions for HFC-32 in self-contained room 
ACs and HPs were requested by industry and allow use consistent with 
the more recent standard, UL 60335-2-40, while also allowing continued 
use with another existing standard, UL 484, until the consensus 
standard setting organization sunsets that older standard; these would 
allow for greater consistency in business practices for different types 
of equipment using the same refrigerant while giving industry time to 
transition between two industry standards. Equipment for HFC-32 already 
manufactured prior to the effective date of this final rule would not 
be affected. Self-contained room ACs and HPs using HFC-32 have been 
subject to similar use conditions, and thus the updated requirements 
result in no adverse impact compared with the absence of this rule. 
Thus, the final rule will not impose new costs on small entities. We 
have therefore concluded that this action will have no net regulatory 
burden for any directly regulated small entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any State, 
local or Tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have Tribal implications as specified in 
Executive Order 13175. It will not have substantial direct effects on 
Tribal governments, on the relationship between the Federal government 
and Indian tribes, or on the distribution of power and responsibilities 
between the Federal government and Indian tribes, as specified in 
Executive Order 13175.Thus, Executive Order 13175 does not apply to 
this action. EPA periodically updates Tribal officials on air 
regulations through the monthly meetings of the National Tribal Air 
Association and will share information on this rulemaking through this 
and other formats.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because EPA does not believe the environmental health or safety risks 
addressed by this action present a disproportionate risk to children. 
While EPA has not conducted a separate analysis of risks to infants and 
children associated with this rule, the rule does contain use 
conditions that would reduce exposure risks to the general population, 
with the reduction of exposure being most important to the most 
sensitive individuals. This action's health and risk assessments are 
contained in the comparisons of toxicity for the various substitutes, 
as well as in the risk screens for the substitutes that are listed in 
this rule. The risk screens are in the docket for this rulemaking.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This action is not subject to Executive Order 13211, because it is 
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act and 1 CFR Part 51

    This action involves technical standards. EPA has decided to use 
and incorporate by reference three technical safety standards in the 
use conditions for the types of refrigeration and air conditioning 
equipment addressed in this action: two standards developed by UL and 
one developed by ASHRAE.
    EPA incorporates by reference the 2019 edition of UL Standard 
60335-2-40, which establishes requirements for the evaluation of 
commercial and residential AC and dehumidifier equipment and safe use 
of flammable refrigerants, among other things. Additionally, EPA uses 
and incorporates by reference the 2021 edition of UL Standard 61010-2-
011, which establishes requirements for the evaluation of laboratory 
equipment and safe use of flammable refrigerants, among other things. 
These standards are discussed in greater detail in sections II.E and 
II.F.4 of this preamble.
    The 2019 UL Standard 60335-2-40 and 2021 UL Standard 61010-2-011 
are available at http://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=36463 and may be purchased by mail at: 
COMM 2000, 151 Eastern Avenue, Bensenville, IL 60106; Email: 
[email protected]; phone: 1-888-853-3503 in the U.S. or Canada 
(other countries dial 1-415-352-2178); website: http://ulstandards.ul.com/ or www.comm-2000.com. The cost of each of the 2019 
UL Standard 60335-2-40 and 2021 UL Standard 61010-2-011 is $440 for an 
electronic copy and $550 for hardcopy. UL also offers a subscription 
service to the Standards Certification Customer Library that allows 
unlimited access to their standards and related documents. The cost of 
obtaining this standard is not a significant financial burden for 
equipment manufacturers and purchase is not necessary for those 
selling, installing, and servicing the equipment. Therefore, EPA 
concludes that the UL standards incorporated by reference is reasonably 
available.
    EPA is also incorporating by reference ANSI/ASHRAE Standard 15-
2019,

[[Page 26416]]

Safety Standard for Refrigeration Systems, in the use conditions for 
six refrigerants listed for use in chillers. This standard concerns the 
safe design, construction, installation, and operation of refrigeration 
systems. This standard is available at https://www.ashrae.org/resources-publications/bookstore/standards-15-34 and may be purchased 
by mail at: 6300 Interfirst Drive, Ann Arbor, MI 48108; by phone: 1-
800-527-4723 in the U.S. or Canada; website: http://www.techstreet.com/ashrae/ashrae_standards.html?ashrae_auth_token=. The cost of ASHRAE 
Standard 15-2019 is $159.00 for an electronic copy or hardcopy. The 
cost of obtaining this standard is not a significant financial burden 
for equipment manufacturers or for those selling, installing and 
servicing the equipment. Therefore, EPA concludes that the ASHRAE 
standard incorporated by reference is reasonably available.
    EPA is incorporating by reference the following addenda to ANSI/
ASHRAE Standard 15-2019, available at https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-addenda:
     Addendum a, ANSI-approved February 6, 2020, concerning 
updates to providing capacity factors for overpressure protection and 
introducing a method for calculating pressure relief capacity factors 
for refrigerants not included in the standard.
     Addendum b, ANSI-approved February 6, 2020, concerning 
updates to the definition of ``listed,'' and adding the term 
``labeled.''
     Addendum c, ANSI-approved September 1, 2020, concerning 
updates to allow the use of equipment using small amounts of non-A1 
refrigerants if they are listed to appropriate safety standards.
     Addendum d, ANSI-approved April 29, 2022, concerning 
clarification that the standard does not apply to residential 
refrigeration systems.
     Addendum e, ANSI-approved January 27, 2022, concerning 
revisions to requirements related to refrigerant piping.
     Addendum f, ANSI-approved September 30, 2020, concerning 
the addition of a new appendix providing clarifying, nonmandatory 
information, movement of mandatory information into the body of the 
standard, and updates to references.
     Addendum i, ANSI-approved July 31, 2020, concerning the 
modification of the standard by deferring regulation of ammonia 
refrigeration to ANSI/IIAR 2 and removal of erroneous references to 
ammonia.
     Addendum j, ANSI-approved October 30, 2020, concerning the 
replacement of the terms ``flammable'' and ``nonflammable'' with the 
specific refrigerant class.
     Addendum k, ANSI-approved October 30, 2020, concerning the 
modification of the existing listing requirement in the standard by 
clarifying the acceptable product safety listing standards.
     Addendum m, ANSI-approved June 30, 2022, concerning the 
modification of allowances for the use of mechanical ventilation to 
expand this mitigation strategy for human comfort applications using 
A2L refrigerants, helping to harmonize the standard with UL 60335-2-40, 
3rd Edition.
     Addendum n, ANSI-approved May 31, 2022, concerning the 
address of a continuous maintenance proposal to clarify wording about 
airflow face velocity.
     Addendum o, ANSI-approved April 29, 2022, concerning the 
clarification of notification requirements.
     Addendum q, ANSI-approved May 31, 2022, concerning the 
modification of requirements for mechanical ventilation in machinery 
rooms using only 2L classified refrigerants, updates to the graphical 
method for determining required ventilation rates, and addition of an 
alternate calculation method for compliance.
     Addendum r, ANSI-approved May 31, 2022, concerning the 
modification of the definition of machinery rooms.
    EPA has already incorporated the following standards into appendix 
R: UL 471 (November 24, 2010); UL 484 (December 21, 2007, with changes 
through August 3, 2012); UL 541 (December 30, 2011); and UL 60335-2-24 
(April 28, 2017).

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) directs 
Federal agencies, to the greatest extent practicable and permitted by 
law, to make environmental justice part of their mission by identifying 
and addressing, as appropriate, disproportionately high and adverse 
human health or environmental effects of their programs, policies, and 
activities on minority populations (people of color and/or Indigenous 
peoples) and low-income populations.
    EPA believes that the human health or environmental conditions that 
exist prior to this action result in or have the potential to result in 
disproportionate and adverse human health or environmental effects on 
people of color, low-income populations and/or indigenous peoples. This 
action's health and environmental risk assessments are contained in the 
comparison of health and environmental risks for HFC-32, HFO-1234yf, R-
452B, R-454A, R-454B, R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and 
Powdered Aerosol H, as well as in the risk screens that are available 
in the docket for this rulemaking. EPA's analysis indicates that other 
environmental impacts and human health impacts of HFC-32, HFO-1234yf, 
R-452B, R-454A, R-454B, R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and 
Powdered Aerosol H are comparable to or less than those of other 
substitutes that are listed as acceptable for the same end-use. Because 
adoption of the new substitutes listed in this final rule is voluntary, 
the Agency is unable to quantify when, where, and how much of the 
listed substitutes will be produced and used. Thus, EPA cannot 
determine the extent to which this rule will exacerbate or reduce 
existing disproportionate adverse effects on communities of color and 
low-income people as specified in Executive Order 12898 (59 FR 7629, 
February 16, 1994).
    EPA believes that it is not practicable to assess whether this 
action is likely to result in new disproportionate and adverse effects 
on people of color, low-income populations and/or indigenous peoples. 
However, the listings for HFC-32, HFO-1234yf, R-452B, R-454A, R-454B, 
R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and Powdered Aerosol H in the 
end-uses addressed in this action provide additional lower-GWP and ODP 
or comparable alternatives in their respective end-uses. By providing 
lower-GWP and ODP or comparable alternatives for these end-uses, this 
rule is anticipated to reduce the use and eventual emissions of potent 
greenhouse gases in these end-uses, which could help to reduce the 
effects of climate change, including the public health and welfare 
effects on people of color, communities of low-income and/or Indigenous 
peoples. The Agency will continue to evaluate the impacts of this 
program on communities with environmental justice concerns and consider 
further action, as appropriate.

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

[[Page 26417]]

IV. References

    Unless specified otherwise, all documents are available 
electronically through the Federal Docket Management System at https://www.regulations.gov, Docket number EPA-HQ-OAR-2021-0836.

ASHRAE, 2019a. ANSI/ASHRAE Standard 34-2019: Designation and Safety 
Classification of Refrigerants.
ASHRAE, 2019b. ANSI/ASHRAE Standard 15-2019: Safety Standard for 
Refrigeration Systems. 2019.
Chemical and Engineering News, 2020. ``CFC replacements are a source 
of persistent organic pollution in the Arctic.'' Katherine Bourzac. 
May 21, 2020. Available online at: https://cen.acs.org/environment/persistent-pollutants/CFC-replacements-source-persistent-organic/98/web/2020/05.
David et al., 2021. ``Trifluoroacetic acid deposition from emissions 
of HFO-1234yf in India, China, and the Middle East,'' Volume 21, 
issue 19. Atmos. Chem. Phys., 21, 14833-14849, 2021. https://doi.org/10.5194/acp-21-14833-2021. Available online at https://
acp.copernicus.org/articles/21/14833/2021/.
``Environmental effects of stratospheric ozone depletion, UV 
radiation, and interactions with climate change: UNEP Environmental 
Efects Assessment Panel, Update 2020.'' Photochemical & 
Photobiological Sciences Available online at: https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.
EEAP, 2021. Environmental Effects of Stratospheric Ozone Depletion, 
UV Radiation, and Interactions with Climate Change: UNEP 
Environmental Effects Assessment Panel, Update 2021. Available 
online at: https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.
Engineering ToolBox, 2005. Refrigerants--Physical Properties. 
Available online at: https://www.engineeringtoolbox.com/refrigerants-d_902.html Accessed October 28, 2021.
EPA, 2004. A Guide to Completing a Risk Screen: Collection and Use 
of Risk Screen Data. Fire Suppression Sector. April 2004.
Freeling et al., 2020. Finnian Freeling, David Behringer, Felix 
Heydel, Marco Scheurer, Thomas A. Ternes, and Karsten N[ouml]dler. 
``Trifluoroacetate in Precipitation: Deriving a Benchmark Data Set'' 
Environ. Sci. Technol. 2020, 54, 18, 11210-11219. August 17, 2020. 
Available online at https://pubs.acs.org/doi/10.1021/acs.est.0c02910.
Freeling et al., 2022. Finnian Freeling, Marco Scheurer, Jan 
Koschorreck, Gabriele Hoffmann, Thomas A. Ternes, and Karsten 
N[ouml]dler. ``Levels and Temporal Trends of Trifluoroacetate (TFA) 
in Archived Plants: Evidence for Increasing Emissions of Gaseous TFA 
Precursors over the Last Decades,'' Environ. Sci. Technol. Lett. 
2022, 9, 5, 400-405. April 18, 2022. Available online at: https://pubs.acs.org/doi/10.1021/acs.estlett.2c00164.
Hodnebrog, et al., 2013. Hodnebrog, [Oslash]., Etminan, M., 
Fuglestvedt, J.S., Marston, G., Myhre, G., Nielsen, C.J., Shine, 
K.P., and Wallington, T.J. (2013). Global Warming Potentials and 
Radiative Efficiencies of Halocarbons and Related Compounds: A 
Comprehensive Review, Reviews of Geophysics, 51, 300-378. Available 
online at doi.org/10.1002/rog.20013.
ICF, 2014. Assessment of the Potential Impact of Hydrocarbon 
Refrigerants on Ground Level Ozone Concentrations. February 2014.
ICF, 2022a. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: R-32.
ICF, 2022b. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: HFO-123yf.
ICF, 2022c. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: R-452B.
ICF, 2022d. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: R-454A.
ICF, 2022e. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: R-454B.
ICF, 2022f. Risk Screen on Substitutes in Chillers and Industrial 
Process Air Conditioning (New Equipment); Substitute: R-454C.
ICF, 2022g. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: HFC-32.
ICF, 2022h. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: R-452B.
ICF, 2022i. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: R-454A.
ICF, 2022j. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: R-454B.
ICF, 2022k. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: R-454C.
ICF, 2022l. Risk Screen on Substitutes in Residential Dehumidifiers 
(New Equipment); Substitute: HFO-1234yf.
ICF, 2022m. [Reserved--not referenced in this document.].
ICF, 2022n. Risk Screen on Substitutes in Residential and Light 
Commercial Air Conditioning and Heat Pumps (New Equipment); 
Substitute: HFC-32 (Difluoromethane).
ICF, 2022o. Risk Screen on Substitutes in Very Low Temperature 
Refrigeration (New Equipment); Substitute: R-1150.
ICF, 2022p. Additional Assessment of the Potential Impact of 
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. May 
2020.
ICF, 2022q. Risk Screen on Substitutes in Total Flooding Systems in 
Normally Unoccupied Spaces. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
ICF, 2022r. Risk Screen on Substitutes as Streaming Agents in Non-
Residential Applications. Substitute: 2-bromo-3,3,3-trifluoropropene 
(2-BTP).
ICF, 2022s. Risk Screen on Substitutes in Total Flooding Systems in 
Normally Unoccupied Spaces; Substitute: EXXFIRE [supreg].
ICF, 2022t. Risk Screen on Substitutes in Total Flooding Systems in 
Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
ICF, 2023a. Risk Screen on Substitutes in Residential and Light 
Commercial Air Conditioning and Heat Pumps (New Equipment); 
Substitute: HFC-32 (Difluoromethane).
ICF, 2023b. Risk Screen on Substitutes in Total Flooding Systems in 
Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
IPCC, 2007. Climate Change 2007: The Physical Science Basis. 
Contribution of Working Group I to the Fourth Assessment Report of 
the Intergovernmental Panel on Climate Change. Solomon, S., Qin, D., 
Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., and 
Miller, H.L. (eds.). Cambridge University Press. Cambridge, United 
Kingdom and New York, NY, USA. Available online at: www.ipcc.ch/
publications_and_data/ar4/wg1/en/contents.html.
Kazil et al., 2014. J. Kazil, S. McKeen, S.-W. Kim, R. Ahmadov, G.A. 
Grell, R.K. Talukdar, A.R. Ravishankara. ``Deposition and rainwater 
concentrations of trifluoroacetic acid in the United States from the 
use of HFO-1234yf,'' JGR Atmospheres. Volume 119, Issue 24. Pages 
14,059-14,079. October 31, 2014. Available online at: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022058.
Kim and Sunderland, 2018. Dennis Kim and Peter Sunderland, 
``Viability of Various Ignition Sources to Ignite A2L Refrigerant 
Leaks,'' 17th International Refrigeration and Air Conditioning 
Conference at Purdue University, July, 2018. Available online at: 
https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2885&context=iracc.
Myhre, et al., 2013. Myhre, G., D. Shindell, F.-M. Br[eacute]on, W. 
Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, 
B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. 
Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: 
Climate Change 2013: The Physical Science Basis. Contribution of 
Working Group I to the Fifth Assessment Report of the 
Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, 
G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. 
Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, 
Cambridge, United Kingdom and New York, NY, USA. Available online 
at: https://www.ipcc.ch/report/ar5/wg1/.
National Fire Protection Agency (NFPA). 2018. NFPA 10: Standard for 
Portable

[[Page 26418]]

Fire Extinguishers. Available online at: https://www.nfpa.org/.
National Fire Protection Agency (NFPA). 2018. NFPA 2001: Standard on 
Clean Agent Fire Extinguishing Systems. Available online at: https://www.nfpa.org/.
National Fire Protection Agency (NFPA). 2018. NFPA 2010. Standard 
for Fixed Aerosol Fire Extinguishing Systems. Available online at: 
https://www.nfpa.org/.
Nielsen et al., 2007. Nielsen, O.J., Javadi, M.S., Sulbaek Andersen, 
M.P., Hurley, M.D., Wallington, T.J., Singh, R. (2007). Atmospheric 
chemistry of CF3CF=CH2: Kinetics and mechanisms of gas-phase 
reactions with Cl atoms, OH radicals, and O3. Chemical Physics 
Letters 439, 18-22. Available online at http://www.lexissecuritiesmosaic.com/gateway/FedReg/network_OJN_174_CF3CF=CH2.pdf.
Orkin, V.L. 2004. Photochemical Properties of 2-bromo-3,3,3-
trfluoropropene and semi-empirical kinetic estimates of its Global 
Impacts on the Atmosphere. Prepared by the National Institute of 
Standards and Technology Physical and Chemical Properties Division 
for American Pacific Corporation. July 2004.
Patten, et al., 2011. Patten, K.O., V.G. Khamaganov, V.L. Orkin, 
S.L. Baughcum, and D.J. Wuebbles (2011), OH reaction rate constant, 
IR absorption spectrum, ozone depletion potentials and global 
warming potentials of 2-bromo-3,3,3-trifluoropropene, J. Geophys. 
Res., 116, D24307, doi:10.1029/2011JD016518.
Patten, et al., 2012. Patten, K.O., V.G. Khamaganov, V.L. Orkin, 
S.L. Baughcum, and D.J. Wuebbles (2012), Correction to ``OH reaction 
rate constant, IR absorption spectrum, ozone depletion potentials 
and global warming potentials of 2-bromo-3,3,3-trifluoropropene,'' 
J. Geophys. Res., 117, D22301, doi:10.1029/2012JD019051.
UL 2129, 2017. UL Standard 2129--Halocarbon Clean Agent Fire 
Extinguishers. Edition 3. January 5, 2017.
UL 60335-2-40, 2019. Household And Similar Electrical Appliances--
Safety--Part 2-40: Particular Requirements for Electrical Heat 
Pumps, Air-Conditioners and Dehumidifiers. Third Edition. November 
1, 2019.
UL Standard 61010-2-011, 2021. Safety Requirements for Electrical 
Equipment for Measurement, Control, and Laboratory Use--Part 011: 
Particular Requirements for Refrigerating Equipment. Second edition. 
May 13, 2021.
Wickham, 2002. Status of Industry Efforts to Replace Halon Fire 
Extinguishing Agents. March 2002. Available online at: https://www.epa.gov/snap/status-industry-efforts-replace-halon-fire-extinguishing-agents.
World Meteorological Organization (WMO), 2018. Burkholder et al. 
Appendix A, Table A-1 in Scientific Assessment of Ozone Depletion: 
2018, Global Ozone Research and Monitoring Project, Report No. 58, 
WMO, Geneva, Switzerland, http://ozone.unep.org/science/assessment/sap.
World Meteorological Organization (WMO), 2022. Executive Summary. 
Scientific Assessment of Ozone Depletion: 2022, GAW Report No. 278, 
56 pp.; WMO: Geneva, 2022. Available online at https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf
Zihan Zhai et al., 2015. Zihan Zhai, Jing Wu, Xia Hu, Li Li, Junyu 
Guo, Boya Zhang, Jianxin Hu, and Jianbo Zhang. ``A 17-fold increase 
of trifluoroacetic acid in landscape waters of Beijing, China during 
the last decade,'' Chemosphere. 2015 Jun; 129:110-7. doi: 10.1016/
j.chemosphere.2014.09.033. Abstract available online at: https://pubmed.ncbi.nlm.nih.gov/25262947/

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Incorporation by reference, Stratospheric ozone 
layer.

Michael S. Regan,
Administrator.

    For the reasons set forth in the preamble, EPA amends 40 CFR part 
82 as follows:

PART 82--PROTECTION OF STRATOSPHERIC OZONE

0
1. The authority citation for part 82 continues to read as follows:

    Authority:  42 U.S.C. 7414, 7601, 7671-7671q.

Subpart G--Significant New Alternatives Policy Program

0
2. Amend appendix R to subpart G of part 82 by:
0
a. Revising the heading;
0
b. Revising the table entitled ``Substitutes That Are Acceptable 
Subject to Use Conditions'' and amending the ``Note'' immediately 
following the table by removing the last two undesignated paragraphs.
    The revisions read as follows:

Appendix R to Subpart G of Part 82--Substitutes Subject to Use 
Restrictions Listed in the December 20, 2011, Final Rule, Effective 
February 21, 2012, and in the April 10, 2015 Final Rule, Effective May 
11, 2015, and in the April 28, 2023 Final Rule, Effective May 30, 2023

                                                Substitutes That Are Acceptable Subject to Use Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
              End-use                      Substitute               Decision                      Use conditions                  Further information
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Household refrigerators,          Isobutane (R-600a)      Acceptable subject to   As of September 7, 2018: These           Applicable OSHA
 freezers, and combination            Propane (R-290) R-      use conditions.         refrigerants may be used only in new     requirements at 29 CFR
 refrigerators and freezers (New      441A.                                           equipment designed specifically and      part 1910 must be
 equipment only).                                                                     clearly identified for the refrigerant   followed, including those
                                                                                      (i.e., none of these substitutes may     at 29 CFR 1910.106
                                                                                      be used as a conversion or               (flammable and
                                                                                      ``retrofit'' refrigerant for existing    combustible liquids),
                                                                                      equipment designed for a different       1910.110 (storage and
                                                                                      refrigerant).                            handling of liquefied
                                                                                     These refrigerants may be used only in    petroleum gases),
                                                                                      a refrigerator or freezer, or            1910.157 (portable fire
                                                                                      combination refrigerator and freezer,    extinguishers), and
                                                                                      that meets all requirements listed in    1910.1000 (toxic and
                                                                                      UL 60335-2-24.1 2 6                      hazardous substances).
                                                                                                                              Proper ventilation should
                                                                                                                               be maintained at all
                                                                                                                               times during the
                                                                                                                               manufacture and storage
                                                                                                                               of equipment containing
                                                                                                                               hydrocarbon refrigerants
                                                                                                                               through adherence to good
                                                                                                                               manufacturing practices
                                                                                                                               as per 29 CFR 1910.106.
                                                                                                                               If refrigerant levels in
                                                                                                                               the air surrounding the
                                                                                                                               equipment rise above one-
                                                                                                                               fourth of the lower
                                                                                                                               flammability limit, the
                                                                                                                               space should be evacuated
                                                                                                                               and re-entry should occur
                                                                                                                               only after the space has
                                                                                                                               been properly ventilated.

[[Page 26419]]

 
                                                                                                                              Technicians and equipment
                                                                                                                               manufacturers should wear
                                                                                                                               appropriate personal
                                                                                                                               protective equipment,
                                                                                                                               including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               these refrigerants.
                                                                                                                               Special care should be
                                                                                                                               taken to avoid contact
                                                                                                                               with the skin since these
                                                                                                                               refrigerants, like many
                                                                                                                               refrigerants, can cause
                                                                                                                               freeze burns on the skin.
                                                                                                                              A Class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.
                                                                                                                              Technicians should only
                                                                                                                               use spark-proof tools
                                                                                                                               when working on
                                                                                                                               refrigerators and
                                                                                                                               freezers with these
                                                                                                                               refrigerants.
                                                                                                                              Any recovery equipment
                                                                                                                               used should be designed
                                                                                                                               for flammable
                                                                                                                               refrigerants. Any
                                                                                                                               refrigerant releases
                                                                                                                               should be in a well-
                                                                                                                               ventilated area, such as
                                                                                                                               outside of a building.
                                                                                                                              Only technicians
                                                                                                                               specifically trained in
                                                                                                                               handling flammable
                                                                                                                               refrigerants should
                                                                                                                               service refrigerators and
                                                                                                                               freezers containing these
                                                                                                                               refrigerants. Technicians
                                                                                                                               should gain an
                                                                                                                               understanding of
                                                                                                                               minimizing the risk of
                                                                                                                               fire and the steps to use
                                                                                                                               flammable refrigerants
                                                                                                                               safely.
2. Retail food refrigerators and     Isobutane (R-600a)      Acceptable subject to   As provided in clauses SB6.1.2 to        Room occupants should
 freezers (stand-alone units only)    Propane (R-290) R-      use conditions.         SB6.1.5 of UL 471,1 2 3 the following    evacuate the space
 (New equipment only).                441A.                                           markings must be attached at the         immediately following the
                                                                                      locations provided and must be           accidental release of
                                                                                      permanent:                               this refrigerant.
                                                                                     (a) On or near any evaporators that can  If a service port is added
                                                                                      be contacted by the consumer:            then retail food
                                                                                      ``DANGER--Risk of Fire or Explosion.     refrigerators and
                                                                                      Flammable Refrigerant Used. Do Not Use   freezers using these
                                                                                      Mechanical Devices To Defrost            refrigerants should have
                                                                                      Refrigerator. Do Not Puncture            service aperture fittings
                                                                                      Refrigerant Tubing.''                    that differ from fittings
                                                                                     (b) Near the machine compartment:         used in equipment or
                                                                                      ``DANGER--Risk of Fire or Explosion.     containers using non-
                                                                                      Flammable Refrigerant Used. To Be        flammable refrigerant.
                                                                                      Repaired Only By Trained Service         ``Differ'' means that
                                                                                      Personnel. Do Not Puncture Refrigerant   either the diameter
                                                                                      Tubing.''                                differs by at least \1/
                                                                                     (c) Near the machine compartment:         16\ inch or the thread
                                                                                      ``CAUTION--Risk of Fire or Explosion.    direction is reversed
                                                                                      Flammable Refrigerant Used. Consult      (i.e., right-handed vs.
                                                                                      Repair Manual/Owner's Guide Before       left-handed). These
                                                                                      Attempting To Service This Product.      different fittings should
                                                                                      All Safety Precautions Must be           be permanently affixed to
                                                                                      Followed.''                              the unit at the point of
                                                                                                                               service and maintained
                                                                                                                               until the end-of-life of
                                                                                                                               the unit, and should not
                                                                                                                               be accessed with an
                                                                                                                               adaptor.
                                                                                        (d) On the exterior of the
                                                                                         refrigerator: ``CAUTION--Risk of
                                                                                         Fire or Explosion. Dispose of
                                                                                         Properly In Accordance With Federal
                                                                                         Or Local Regulations. Flammable
                                                                                         Refrigerant Used.''
                                                                                     (e) Near any and all exposed
                                                                                      refrigerant tubing: ``CAUTION--Risk of
                                                                                      Fire or Explosion Due To Puncture Of
                                                                                      Refrigerant Tubing; Follow Handling
                                                                                      Instructions Carefully. Flammable
                                                                                      Refrigerant Used.''
                                                                                     All of these markings must be in
                                                                                      letters no less than 6.4 mm (\1/4\
                                                                                      inch) high.
                                                                                     The refrigerator or freezer must have
                                                                                      red, Pantone[supreg] Matching System
                                                                                      (PMS) #185 marked pipes, hoses, and
                                                                                      other devices through which the
                                                                                      refrigerant is serviced, typically
                                                                                      known as the service port, to indicate
                                                                                      the use of a flammable refrigerant.
                                                                                      This color must be present at all
                                                                                      service ports and where service
                                                                                      puncturing or otherwise creating an
                                                                                      opening from the refrigerant circuit
                                                                                      to the atmosphere might be expected
                                                                                      (e.g., process tubes). The color mark
                                                                                      must extend at least 2.5 centimeters
                                                                                      (1 inch) from the compressor and must
                                                                                      be replaced if removed.
3. Very low temperature              Ethane (R-170)........  Acceptable subject to   This refrigerant may be used only in     Applicable OSHA
 refrigeration Non-mechanical heat                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 transfer (New equipment only).                                                       and clearly identified for the           part 1910 must be
                                                                                      refrigerant (i.e., the substitute may    followed, including those
                                                                                      not be used as a conversion or           at 29 CFR 1910.94
                                                                                      ``retrofit'' refrigerant for existing    (ventilation) and
                                                                                      equipment designed for other             1910.106 (flammable and
                                                                                      refrigerants).                           combustible liquids),
                                                                                     This refrigerant may only be used in      1910.110 (storage and
                                                                                      equipment that meets all requirements    handling of liquefied
                                                                                      in Supplement SB to UL 471.1 2 3 In      petroleum gases),
                                                                                      cases where listing 3 of this table      1910.157 (portable fire
                                                                                      includes requirements more stringent     extinguishers), and
                                                                                      than those of UL 471, the appliance      1910.1000 (toxic and
                                                                                      must meet the requirements of listing    hazardous substances).
                                                                                      3 of this table in place of the         Proper ventilation should
                                                                                      requirements in UL 471.                  be maintained at all
                                                                                     The charge size for the equipment must    times during the
                                                                                      not exceed 150 g (5.29 oz) in each       manufacture and storage
                                                                                      circuit.                                 of equipment containing
                                                                                     As provided in clauses SB6.1.2 to         hydrocarbon refrigerants
                                                                                      SB6.1.5 of UL 471,1 2 3 the following    through adherence to good
                                                                                      markings must be attached at the         manufacturing practices
                                                                                      locations provided and must be           as per 29 CFR 1910.106.
                                                                                      permanent:                               If refrigerant levels in
                                                                                     (a) On or near any evaporators that can   the air surrounding the
                                                                                      be contacted by the consumer:            equipment rise above one-
                                                                                      ``DANGER--Risk of Fire or Explosion.     fourth of the lower
                                                                                      Flammable Refrigerant Used. Do Not Use   flammability limit, the
                                                                                      Mechanical Devices To Defrost            space should be evacuated
                                                                                      Refrigerator. Do Not Puncture            and re-entry should occur
                                                                                      Refrigerant Tubing.''                    only after the space has
                                                                                                                               been properly ventilated.
                                                                                                                              Technicians and equipment
                                                                                                                               manufacturers should wear
                                                                                                                               appropriate personal
                                                                                                                               protective equipment,
                                                                                                                               including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               ethane. Special care
                                                                                                                               should be taken to avoid
                                                                                                                               contact with the skin
                                                                                                                               since ethane, like many
                                                                                                                               refrigerants, can cause
                                                                                                                               freeze burns on the skin.
                                                                                                                              A Class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.

[[Page 26420]]

 
                                                                                        (b) Near the machine compartment:     Technicians should only
                                                                                         ``DANGER--Risk of Fire or             use spark-proof tools
                                                                                         Explosion. Flammable Refrigerant      when working on equipment
                                                                                         Used. To Be Repaired Only By          with flammable
                                                                                         Trained Service Personnel. Do Not     refrigerants.
                                                                                         Puncture Refrigerant Tubing.''       Any recovery equipment
                                                                                     (c) Near the machine compartment:         used should be designed
                                                                                      ``CAUTION--Risk of Fire or Explosion.    for flammable
                                                                                      Flammable Refrigerant Used. Consult      refrigerants.
                                                                                      Repair Manual/Owner's Guide Before      Any refrigerant releases
                                                                                      Attempting To Service This Product.      should be in a well-
                                                                                      All Safety Precautions Must be           ventilated area, such as
                                                                                      Followed.''                              outside of a building.
                                                                                     (d) On the exterior of the               Only technicians
                                                                                      refrigerator: ``CAUTION--Risk of Fire    specifically trained in
                                                                                      or Explosion. Dispose of Properly In     handling flammable
                                                                                      Accordance With Federal Or Local         refrigerants should
                                                                                      Regulations. Flammable Refrigerant       service equipment
                                                                                      Used.''                                  containing ethane.
                                                                                     (e) Near any and all exposed              Technicians should gain
                                                                                      refrigerant tubing: ``CAUTION--Risk of   an understanding of
                                                                                      Fire or Explosion Due To Puncture Of     minimizing the risk of
                                                                                      Refrigerant Tubing; Follow Handling      fire and the steps to use
                                                                                      Instructions Carefully. Flammable        flammable refrigerants
                                                                                      Refrigerant Used.''                      safely.
                                                                                     All of these markings must be in         Room occupants should
                                                                                      letters no less than 6.4 mm (\1/4\       evacuate the space
                                                                                      inch) high.                              immediately following the
                                                                                     The refrigeration equipment must have     accidental release of
                                                                                      red, Pantone[supreg] Matching System     this refrigerant.
                                                                                      (PMS) #185 marked pipes, hoses, and     If a service port is added
                                                                                      other devices through which the          then refrigeration
                                                                                      refrigerant is serviced, typically       equipment using this
                                                                                      known as the service port, to indicate   refrigerant should have
                                                                                      the use of a flammable refrigerant.      service aperture fittings
                                                                                      This color must be present at all        that differ from fittings
                                                                                      service ports and where service          used in equipment or
                                                                                      puncturing or otherwise creating an      containers using non-
                                                                                      opening from the refrigerant circuit     flammable refrigerant.
                                                                                      to the atmosphere might be expected      ``Differ'' means that
                                                                                      (e.g., process tubes). The color mark    either the diameter
                                                                                      must extend at least 2.5 centimeters     differs by at least \1/
                                                                                      (1 inch) from the compressor and must    16\ inch or the thread
                                                                                      be replaced if removed.                  direction is reversed
                                                                                                                               (i.e., right-handed vs.
                                                                                                                               left-handed). These
                                                                                                                               different fittings should
                                                                                                                               be permanently affixed to
                                                                                                                               the unit at the point of
                                                                                                                               service and maintained
                                                                                                                               until the end-of-life of
                                                                                                                               the unit, and should not
                                                                                                                               be accessed with an
                                                                                                                               adaptor.
                                                                                                                              Example of non-mechanical
                                                                                                                               heat transfer using this
                                                                                                                               refrigerant would be use
                                                                                                                               in a secondary loop of a
                                                                                                                               thermosiphon.
4. Vending Machines (New equipment   Isobutane (R-600a)      Acceptable subject to   These refrigerants may be used only in   Applicable OSHA
 only).                               Propane (R-290) R-      use conditions.         new equipment specifically designed      requirements at 29 CFR
                                      441A.                                           and clearly identified for the           part 1910 must be
                                                                                      refrigerants (i.e., none of these        followed, including those
                                                                                      substitutes may be used as a             at 29 CFR 1910.94
                                                                                      conversion or ``retrofit'' refrigerant   (ventilation) and
                                                                                      for existing equipment designed for      1910.106 (flammable and
                                                                                      other refrigerants). Detaching and       combustible liquids),
                                                                                      replacing the old refrigeration          1910.110 (storage and
                                                                                      circuit from the outer casing of the     handling of liquefied
                                                                                      equipment with a new one containing a    petroleum gases),
                                                                                      new evaporator, condenser, and           1910.157 (portable fire
                                                                                      refrigerant tubing within the old        extinguishers), and
                                                                                      casing is considered ``new'' equipment   1910.1000 (toxic and
                                                                                      and not a retrofit of the old,           hazardous substances).
                                                                                      existing equipment.                     Proper ventilation should
                                                                                     These substitutes may only be used in     be maintained at all
                                                                                      equipment that meets all requirements    times during the
                                                                                      in Supplement SA to UL 541.1 2 5 In      manufacture and storage
                                                                                      cases where listing 4 of this table      of equipment containing
                                                                                      includes requirements more stringent     hydrocarbon refrigerants
                                                                                      than those of UL 541, the appliance      through adherence to good
                                                                                      must meet the requirements of listing    manufacturing practices
                                                                                      4 of this table in place of the          as per 29 CFR 1910.106.
                                                                                      requirements in UL 541 The charge size   If refrigerant levels in
                                                                                      for vending machines must not exceed     the air surrounding the
                                                                                      150 g (5.29 oz) in each circuit.         equipment rise above one-
                                                                                     As provided in clauses SA6.1.2 to         fourth of the lower
                                                                                      SA6.1.5 of UL 541,1 2 5 the following    flammability limit, the
                                                                                      markings must be attached at the         space should be evacuated
                                                                                      locations provided and must be           and re-entry should occur
                                                                                      permanent:                               only after the space has
                                                                                                                               been properly ventilated.
                                                                                                                              Technicians and equipment
                                                                                                                               manufacturers should wear
                                                                                                                               appropriate personal
                                                                                                                               protective equipment,
                                                                                                                               including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               these refrigerants.
                                                                                                                               Special care should be
                                                                                                                               taken to avoid contact
                                                                                                                               with the skin since these
                                                                                                                               refrigerants, like many
                                                                                                                               refrigerants, can cause
                                                                                                                               freeze burns on the skin.
                                                                                                                              A Class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.
                                                                                        (a) On or near any evaporators that   Technicians should only
                                                                                         can be contacted by the consumer:     use spark-proof tools
                                                                                         ``DANGER--Risk of Fire or             when working on
                                                                                         Explosion. Flammable Refrigerant      refrigeration equipment
                                                                                         Used. Do Not Use Mechanical Devices   with flammable
                                                                                         To Defrost Refrigerator. Do Not       refrigerants.
                                                                                         Puncture Refrigerant Tubing.''       Any recovery equipment
                                                                                     (b) Near the machine compartment:         used should be designed
                                                                                      ``DANGER--Risk of Fire or Explosion.     for flammable
                                                                                      Flammable Refrigerant Used. To Be        refrigerants.
                                                                                      Repaired Only By Trained Service        Any refrigerant releases
                                                                                      Personnel. Do Not Puncture Refrigerant   should be in a well-
                                                                                      Tubing.''                                ventilated area, such as
                                                                                     (c) Near the machine compartment:         outside of a building.
                                                                                      ``CAUTION--Risk of Fire or Explosion.   Only technicians
                                                                                      Flammable Refrigerant Used. Consult      specifically trained in
                                                                                      Repair Manual/Owner's Guide Before       handling flammable
                                                                                      Attempting To Service This Product.      refrigerants should
                                                                                      All Safety Precautions Must be           service refrigeration
                                                                                      Followed.''                              equipment containing
                                                                                     (d) On the exterior of the                these refrigerants.
                                                                                      refrigerator: ``CAUTION--Risk of Fire    Technicians should gain
                                                                                      or Explosion. Dispose of Properly In     an understanding of
                                                                                      Accordance With Federal Or Local         minimizing the risk of
                                                                                      Regulations. Flammable Refrigerant       fire and the steps to use
                                                                                      Used.''                                  flammable refrigerants
                                                                                     (e) Near any and all exposed              safely.
                                                                                      refrigerant tubing: ``CAUTION--Risk of  Room occupants should
                                                                                      Fire or Explosion Due To Puncture Of     evacuate the space
                                                                                      Refrigerant Tubing; Follow Handling      immediately following the
                                                                                      Instructions Carefully. Flammable        accidental release of
                                                                                      Refrigerant Used.'' All of these         this refrigerant.
                                                                                      markings must be in letters no less     If a service port is added
                                                                                      than 6.4 mm (\1/4\ inch) high.           then refrigeration
                                                                                                                               equipment using this
                                                                                                                               refrigerant should have
                                                                                                                               service aperture fittings
                                                                                                                               that differ from fittings
                                                                                                                               used in equipment or
                                                                                                                               containers using non-
                                                                                                                               flammable refrigerant.
                                                                                                                               ``Differ'' means that
                                                                                                                               either the diameter
                                                                                                                               differs by at least \1/
                                                                                                                               16\ inch or the thread
                                                                                                                               direction is reversed
                                                                                                                               (i.e., right-handed vs.
                                                                                                                               left-handed). These
                                                                                                                               different fittings should
                                                                                                                               be permanently affixed to
                                                                                                                               the unit at the point of
                                                                                                                               service and maintained
                                                                                                                               until the end-of-life of
                                                                                                                               the unit, and should not
                                                                                                                               be accessed with an
                                                                                                                               adaptor.

[[Page 26421]]

 
                                                                                     The refrigeration equipment must have
                                                                                      red, Pantone[supreg] Matching System
                                                                                      (PMS) #185 marked pipes, hoses, and
                                                                                      other devices through which the
                                                                                      refrigerant is serviced, typically
                                                                                      known as the service port, to indicate
                                                                                      the use of a flammable refrigerant.
                                                                                      This color must be present at all
                                                                                      service ports and where service
                                                                                      puncturing or otherwise creating an
                                                                                      opening from the refrigerant circuit
                                                                                      to the atmosphere might be expected
                                                                                      (e.g., process tubes). The color mark
                                                                                      must extend at least 2.5 centimeters
                                                                                      (1 inch) from the compressor and must
                                                                                      be replaced if removed.
5. Residential and light-commercial  Propane (R-290) R-441A  Acceptable subject to   These refrigerants may be used only in   Applicable OSHA
 air conditioning and heat pumps--                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerants (i.e., none of these        followed, including those
 only).                                                                               substitutes may be used as a             at 29 CFR 1910.94
                                                                                      conversion or ``retrofit'' refrigerant   (ventilation) and
                                                                                      for existing equipment designed for      1910.106 (flammable and
                                                                                      other refrigerants).                     combustible liquids),
                                                                                     These refrigerants may only be used in    1910.110 (storage and
                                                                                      equipment that meets all requirements    handling of liquefied
                                                                                      in Supplement SA and Appendices B        petroleum gases),
                                                                                      through F of UL 484.1 2 4 In cases       1910.157 (portable fire
                                                                                      where listing 5 includes requirements    extinguishers), and
                                                                                      more stringent than those of UL 484,     1910.1000 (toxic and
                                                                                      the appliance must meet the              hazardous substances).
                                                                                      requirements of listing 5 of this       Proper ventilation should
                                                                                      table in place of the requirements in    be maintained at all
                                                                                      UL 484.                                  times during the
                                                                                     The charge size for the entire air        manufacture and storage
                                                                                      conditioner must not exceed the          of equipment containing
                                                                                      maximum refrigerant mass determined      hydrocarbon refrigerants
                                                                                      according to Appendix F of UL 484 for    through adherence to good
                                                                                      the room size where the air              manufacturing practices
                                                                                      conditioner is used. The charge size     as per 29 CFR 1910.106.
                                                                                      for these three refrigerants must in     If refrigerant levels in
                                                                                      no case exceed 1,000 g (35.3 oz or       the air surrounding the
                                                                                      2.21 lbs) of propane or 1,000 g (35.3    equipment rise above one-
                                                                                      oz or 2.21 lb) of R-441A. For portable   fourth of the lower
                                                                                      air conditioners, the charge size must   flammability limit, the
                                                                                      in no case exceed 300 g (10.6 oz or      space should be evacuated
                                                                                      0.66 lbs) of propane or 330 g (11.6 oz   and re-entry should occur
                                                                                      or 0.72 lb) of R-441A. The               only after the space has
                                                                                      manufacturer must design a charge size   been properly ventilated.
                                                                                      for the entire air conditioner that     Technicians and equipment
                                                                                      does not exceed the amount specified     manufacturers should wear
                                                                                      for the unit's cooling capacity, as      appropriate personal
                                                                                      specified in table A, B, C, D, or E of   protective equipment,
                                                                                      this appendix R.                         including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               these refrigerants.
                                                                                                                               Special care should be
                                                                                                                               taken to avoid contact
                                                                                                                               with the skin since these
                                                                                                                               refrigerants, like many
                                                                                                                               refrigerants, can cause
                                                                                                                               freeze burns on the skin.
                                                                                                                              A Class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.
                                                                                                                              Technicians should only
                                                                                                                               use spark-proof tools
                                                                                                                               when working on air
                                                                                                                               conditioning equipment
                                                                                                                               with flammable
                                                                                                                               refrigerants.
                                                                                     As provided in clauses SA6.1.2 to        Any recovery equipment
                                                                                      SA6.1.5 of UL 484,1 2 4 the following    used should be designed
                                                                                      markings must be attached at the         for flammable
                                                                                      locations provided and must be           refrigerants.
                                                                                      permanent:                              Any refrigerant releases
                                                                                     (a) On the outside of the air             should be in a well-
                                                                                      conditioner: ``DANGER--Risk of Fire or   ventilated area, such as
                                                                                      Explosion. Flammable Refrigerant Used.   outside of a building.
                                                                                      To Be Repaired Only By Trained Service  Only technicians
                                                                                      Personnel. Do Not Puncture Refrigerant   specifically trained in
                                                                                      Tubing.''                                handling flammable
                                                                                     (b) On the outside of the air             refrigerants should
                                                                                      conditioner: ``CAUTION--Risk of Fire     service refrigeration
                                                                                      or Explosion. Dispose of Properly In     equipment containing
                                                                                      Accordance With Federal Or Local         these refrigerants.
                                                                                      Regulations. Flammable Refrigerant       Technicians should gain
                                                                                      Used.''                                  an understanding of
                                                                                     (c) On the inside of the air              minimizing the risk of
                                                                                      conditioner near the compressor:         fire and the steps to use
                                                                                      ``CAUTION--Risk of Fire or Explosion.    flammable refrigerants
                                                                                      Flammable Refrigerant Used. Consult      safely.
                                                                                      Repair Manual/Owner's Guide Before      Room occupants should
                                                                                      Attempting To Service This Product.      evacuate the space
                                                                                      All Safety Precautions Must be           immediately following the
                                                                                      Followed.''                              accidental release of
                                                                                     (d) On the outside of each portable air   this refrigerant.
                                                                                      conditioner: ``WARNING: Appliance       If a service port is added
                                                                                      shall be installed, operated and         then air conditioning
                                                                                      stored in a room with a floor area       equipment using this
                                                                                      larger the ``X'' m\2\ (Y ft\2\).'' The   refrigerant should have
                                                                                      value ``X'' on the label must be         service aperture fittings
                                                                                      determined using the minimum room size   that differ from fittings
                                                                                      in m\2\ calculated using Appendix F of   used in equipment or
                                                                                      UL 484. For R-441A, use a lower          containers using non-
                                                                                      flammability limit of 0.041 kg/m\3\ in   flammable refrigerant.
                                                                                      calculations in Appendix F of UL 484.    ``Differ'' means that
                                                                                                                               either the diameter
                                                                                                                               differs by at least \1/
                                                                                                                               16\ inch or the thread
                                                                                                                               direction is reversed
                                                                                                                               (i.e., right-handed vs.
                                                                                                                               left-handed). These
                                                                                                                               different fittings should
                                                                                                                               be permanently affixed to
                                                                                                                               the unit at the point of
                                                                                                                               service and maintained
                                                                                                                               until the end-of-life of
                                                                                                                               the unit, and should not
                                                                                                                               be accessed with an
                                                                                                                               adaptor.
                                                                                                                              Air conditioning equipment
                                                                                                                               in this category
                                                                                                                               includes:
                                                                                                                              Window air conditioning
                                                                                                                               units.
                                                                                                                              Portable room air
                                                                                                                               conditioners.
                                                                                                                              Packaged terminal air
                                                                                                                               conditioners and heat
                                                                                                                               pumps.
                                                                                     All of these markings must be in
                                                                                      letters no less than 6.4 mm (\1/4\
                                                                                      inch) high.
                                                                                     The air conditioning equipment must
                                                                                      have red, Pantone[supreg] Matching
                                                                                      System (PMS) #185 marked pipes, hoses,
                                                                                      and other devices through which the
                                                                                      refrigerant is serviced, typically
                                                                                      known as the service port, to indicate
                                                                                      the use of a flammable refrigerant.
                                                                                      This color must be present at all
                                                                                      service ports and where service
                                                                                      puncturing or otherwise creating an
                                                                                      opening from the refrigerant circuit
                                                                                      to the atmosphere might be expected
                                                                                      (e.g., process tubes). The color mark
                                                                                      must extend at least 2.5 centimeters
                                                                                      (1 inch) from the compressor and must
                                                                                      be replaced if removed.

[[Page 26422]]

 
6. Residential and light-commercial  HFC-32................  Acceptable subject to   This refrigerant may be used only in     Applicable OSHA
 air conditioning and heat pumps--                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerant (i.e., this substitute may   followed, including those
 only) manufactured from May 10,                                                      not be used as a conversion or           at 29 CFR 1910.94
 2015 and up to but not including                                                     ``retrofit'' refrigerant for existing    (ventilation) and
 May 30, 2023.                                                                        equipment designed for other             1910.106 (flammable and
                                                                                      refrigerants).                           combustible liquids),
                                                                                     This refrigerant may only be used in      1910.110 (storage and
                                                                                      equipment that meets all requirements    handling of liquefied
                                                                                      in Supplement SA and Appendices B        petroleum gases),
                                                                                      through F of UL 484.1 2 4 In cases       1910.157 (portable fire
                                                                                      where this listing 6 of this table       extinguishers), and
                                                                                      includes requirements more stringent     1910.1000 (toxic and
                                                                                      than those of UL 484, the appliance      hazardous substances).
                                                                                      must meet the requirements of listing   Proper ventilation should
                                                                                      6 of this table in place of the          be maintained at all
                                                                                      requirements in UL 484.                  times during the
                                                                                     The charge size for the entire air        manufacture and storage
                                                                                      conditioner must not exceed the          of equipment containing
                                                                                      maximum refrigerant mass determined      hydrocarbon refrigerants
                                                                                      according to Appendix F of UL 484 for    through adherence to good
                                                                                      the room size where the air              manufacturing practices
                                                                                      conditioner is used. The manufacturer    as per 29 CFR 1910.106.
                                                                                      must design a charge size for the        If refrigerant levels in
                                                                                      entire air conditioner that does not     the air surrounding the
                                                                                      exceed the amount specified for the      equipment rise above one-
                                                                                      unit's cooling capacity, as specified    fourth of the lower
                                                                                      in table A, B, C, D, or E of this        flammability limit, the
                                                                                      appendix.                                space should be evacuated
                                                                                                                               and re-entry should occur
                                                                                                                               only after the space has
                                                                                                                               been properly ventilated.
                                                                                                                              Technicians and equipment
                                                                                                                               manufacturers should wear
                                                                                                                               appropriate personal
                                                                                                                               protective equipment,
                                                                                                                               including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               these refrigerants.
                                                                                                                               Special care should be
                                                                                                                               taken to avoid contact
                                                                                                                               with the skin since these
                                                                                                                               refrigerants, like many
                                                                                                                               refrigerants, can cause
                                                                                                                               freeze burns on the skin.
                                                                                     For equipment following this listing 6,  A Class B dry powder type
                                                                                      and as provided in clauses SA6.1.2 to    fire extinguisher should
                                                                                      SA6.1.5 of UL 484,1 2 4 the following    be kept nearby.
                                                                                      markings must be attached at the        Technicians should only
                                                                                      locations provided and must be           use spark-proof tools
                                                                                      permanent:                               when working on air
                                                                                     (a) On the outside of the air             conditioning equipment
                                                                                      conditioner: ``DANGER--Risk of Fire or   with flammable
                                                                                      Explosion. Flammable Refrigerant Used.   refrigerants.
                                                                                      To Be Repaired Only By Trained Service  Any recovery equipment
                                                                                      Personnel. Do Not Puncture Refrigerant   used should be designed
                                                                                      Tubing.''                                for flammable
                                                                                     (b) On the outside of the air             refrigerants.
                                                                                      conditioner: ``CAUTION--Risk of Fire    Any refrigerant releases
                                                                                      or Explosion. Dispose of Properly In     should be in a well-
                                                                                      Accordance With Federal Or Local         ventilated area, such as
                                                                                      Regulations. Flammable Refrigerant       outside of a building.
                                                                                      Used.''                                 Only technicians
                                                                                                                               specifically trained in
                                                                                                                               handling flammable
                                                                                                                               refrigerants should
                                                                                                                               service refrigeration
                                                                                                                               equipment containing
                                                                                                                               these refrigerants.
                                                                                                                               Technicians should gain
                                                                                                                               an understanding of
                                                                                                                               minimizing the risk of
                                                                                                                               fire and the steps to use
                                                                                                                               flammable refrigerants
                                                                                                                               safely.
                                                                                        (c) On the inside of the air          Room occupants should
                                                                                         conditioner near the compressor:      evacuate the space
                                                                                         ``CAUTION--Risk of Fire or            immediately following the
                                                                                         Explosion. Flammable Refrigerant      accidental release of
                                                                                         Used. Consult Repair Manual/Owner's   this refrigerant.
                                                                                         Guide Before Attempting To Service   If a service port is added
                                                                                         This Product. All Safety              then air conditioning
                                                                                         Precautions Must be Followed.''       equipment using this
                                                                                     (d) On the outside of each portable air   refrigerant should have
                                                                                      conditioner: ``WARNING: Appliance        service aperture fittings
                                                                                      shall be installed, operated and         that differ from fittings
                                                                                      stored in a room with a floor area       used in equipment or
                                                                                      larger the ``X'' m\2\ (Y ft\2\).'' The   containers using non-
                                                                                      value ``X'' on the label must be         flammable refrigerant.
                                                                                      determined using the minimum room size   ``Differ'' means that
                                                                                      in m\2\ calculated using Appendix F of   either the diameter
                                                                                      UL 484.                                  differs by at least \1/
                                                                                     All of these markings must be in          16\ inch or the thread
                                                                                      letters no less than 6.4 mm (\1/4\       direction is reversed
                                                                                      inch) high.                              (i.e., right-handed vs.
                                                                                     The air conditioning equipment must       left-handed). These
                                                                                      have red, Pantone[supreg] Matching       different fittings should
                                                                                      System (PMS) #185 marked pipes, hoses,   be permanently affixed to
                                                                                      and other devices through which the      the unit at the point of
                                                                                      refrigerant is serviced, typically       service and maintained
                                                                                      known as the service port, to indicate   until the end-of-life of
                                                                                      the use of a flammable refrigerant.      the unit, and should not
                                                                                      This color must be present at all        be accessed with an
                                                                                      service ports and where service          adaptor.
                                                                                      puncturing or otherwise creating an     Air conditioning equipment
                                                                                      opening from the refrigerant circuit     in this category
                                                                                      to the atmosphere might be expected      includes:
                                                                                      (e.g., process tubes). The color mark   Window air conditioning
                                                                                      must extend at least 2.5 centimeters     units.
                                                                                      (1 inch) from the compressor and must   Portable room air
                                                                                      be replaced if removed.                  conditioners.
                                                                                                                              Packaged terminal air
                                                                                                                               conditioners and heat
                                                                                                                               pumps.
7. Residential and light-commercial  HFC-32................  Acceptable subject to   This refrigerant may only be used in
 air conditioning and heat pumps--                            use conditions.         equipment that meets all requirements
 self-contained room air                                                              in either:
 conditioners only (New equipment                                                    (1) Supplement SA and Appendices B
 only) manufactured from May 30,                                                      through F of UL 484 1 2 4 and listing
 2023 through January 1, 2024.                                                        6 of this table, or
                                                                                     (2) UL 60335-2-40 1 2 7 and listing 8
                                                                                      of this table.
8. Residential and light-commercial  HFC-32................  Acceptable Subject to   This refrigerant may be used only in     Applicable OSHA
 air conditioning and heat pumps--                            Use Conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerant (i.e., this substitute may   followed, including those
 only) manufactured on or after                                                       not be used as a conversion or           at 29 CFR 1910.94
 January 2, 2024.                                                                     ``retrofit'' refrigerant for existing    (ventilation) and
                                                                                      equipment designed for other             1910.106 (flammable and
                                                                                      refrigerants).                           combustible liquids),
                                                                                     This substitute may only be used in air   1910.110 (storage and
                                                                                      conditioning equipment that meets all    handling of liquefied
                                                                                      requirements in UL 60335-2-40 1 2 7      petroleum gases), and
                                                                                      and this listing 8 of this table.        1910.1000 (toxic and
                                                                                     In cases where this listing 8 includes    hazardous substances).
                                                                                      requirements more stringent than those  Proper ventilation should
                                                                                      of UL 60335-2-40, the appliance must     be maintained at all
                                                                                      meet the requirements of this listing    times during the
                                                                                      8 in place of the requirements in UL     manufacture and storage
                                                                                      60335-2-40.                              of equipment containing
                                                                                     The following markings must be attached   flammable refrigerants
                                                                                      at the locations provided and must be    through adherence to good
                                                                                      permanent:                               manufacturing practices
                                                                                                                               as per 29 CFR 1910.106.
                                                                                                                               If refrigerant levels in
                                                                                                                               the air surrounding the
                                                                                                                               equipment rise above one-
                                                                                                                               fourth of the lower
                                                                                                                               flammability limit, the
                                                                                                                               space should be
                                                                                                                               evacuated, and reentry
                                                                                                                               should occur only after
                                                                                                                               the space has been
                                                                                                                               properly ventilated.

[[Page 26423]]

 
                                                                                        (a) On the outside of the equipment:  Technicians and equipment
                                                                                         ``WARNING--Risk of Fire. Flammable    manufacturers should wear
                                                                                         Refrigerant Used. To Be Repaired      appropriate personal
                                                                                         Only By Trained Service Personnel.    protective equipment,
                                                                                         Do Not Puncture Refrigerant           including chemical
                                                                                         Tubing.''                             goggles and protective
                                                                                     (b) On the outside of the equipment:      gloves, when handling
                                                                                      ``WARNING--Risk of Fire. Dispose of      flammable refrigerants.
                                                                                      Properly In Accordance With Federal Or   Special care should be
                                                                                      Local Regulations. Flammable             taken to avoid contact
                                                                                      Refrigerant Used.''                      with the skin which, like
                                                                                                                               many refrigerants, can
                                                                                                                               cause freeze burns on the
                                                                                                                               skin.
                                                                                                                              A class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.
                                                                                        (c) On the inside of the equipment    Technicians should only
                                                                                         near the compressor: ``WARNING--      use spark-proof tools
                                                                                         Risk of Fire. Flammable Refrigerant   when working on air
                                                                                         Used. Consult Repair Manual/Owner's   conditioning equipment
                                                                                         Guide Before Attempting to Service    with flammable
                                                                                         This Product. All Safety              refrigerants.
                                                                                         Precautions Must be Followed.''      Any recovery equipment
                                                                                     (d) For any equipment pre-charged at      used should be designed
                                                                                      the factory, on the equipment            for flammable
                                                                                      packaging or on the outside of the       refrigerants. Only
                                                                                      equipment: ``WARNING--Risk of Fire due   technicians specifically
                                                                                      to Flammable Refrigerant Used. Follow    trained in handling
                                                                                      Handling Instructions Carefully in       flammable refrigerants
                                                                                      Compliance with National                 should service
                                                                                      Regulations.''                           refrigeration equipment
                                                                                     a. If the equipment is delivered          containing this
                                                                                      packaged, this label shall be applied    refrigerant. Technicians
                                                                                      on the packaging.                        should gain an
                                                                                     b. If the equipment is not delivered      understanding of
                                                                                      packaged, this label shall be applied    minimizing the risk of
                                                                                      on the outside of the equipment near     fire and the steps to use
                                                                                      the control panel or nameplate.          flammable refrigerants
                                                                                     (e) On the equipment near the             safely.
                                                                                      nameplate:                              Room occupants should
                                                                                     a. At the top of the marking: ``Minimum   evacuate the space
                                                                                      Installation height, X m (W ft).''       immediately following the
                                                                                      This marking is only required if         accidental release of
                                                                                      required by the UL 60335-2-40. The       this refrigerant.
                                                                                      terms ``X'' and ``W'' shall be          Personnel commissioning,
                                                                                      replaced by the numeric height as        maintaining, repairing,
                                                                                      calculated per UL 60335-2-40. Note       decommissioning and
                                                                                      that the formatting here is slightly     disposing of appliances
                                                                                      different than UL 60335-2-40;            with this refrigerant
                                                                                      specifically, the height in Inch-Pound   should obtain training
                                                                                      units is placed in parentheses and the   and follow practices
                                                                                      word ``and'' has been replaced by the    consistent with Annex HH
                                                                                      opening parenthesis.                     of UL 60335-2-40.2 7
                                                                                                                              CAA section 608(c)(2)
                                                                                                                               prohibits knowingly
                                                                                                                               venting or otherwise
                                                                                                                               knowingly releasing or
                                                                                                                               disposing of substitute
                                                                                                                               refrigerants in the
                                                                                                                               course of maintaining,
                                                                                                                               servicing, repairing or
                                                                                                                               disposing of an appliance
                                                                                                                               or industrial process
                                                                                                                               refrigeration.
                                                                                                                              Department of
                                                                                                                               Transportation
                                                                                                                               requirements for
                                                                                                                               transport of flammable
                                                                                                                               gases must be followed.
                                                                                                                              Flammable refrigerants
                                                                                                                               being recovered or
                                                                                                                               otherwise disposed of
                                                                                                                               from residential and
                                                                                                                               light commercial air
                                                                                                                               conditioning appliances
                                                                                                                               are likely to be
                                                                                                                               hazardous waste under the
                                                                                                                               Resource Conservation and
                                                                                                                               Recovery Act (RCRA) (see
                                                                                                                               40 CFR parts 260 through
                                                                                                                               270).
                                                                                          b. Immediately below marking (a)
                                                                                           of this listing 8 or at the top
                                                                                           of the marking if marking (a) is
                                                                                           not required: ``Minimum room area
                                                                                           (operating or storage), Y m\2\ (Z
                                                                                           ft\2\).'' The terms ``Y'' and
                                                                                           ``Z'' shall be replaced by the
                                                                                           numeric area as calculated per UL
                                                                                           60335-2-40. Note that the
                                                                                           formatting here is slightly
                                                                                           different than UL 60335-2-40;
                                                                                           specifically, the area in Inch-
                                                                                           Pound units is placed in
                                                                                           parentheses and the word ``and''
                                                                                           has been replaced by the opening
                                                                                           parenthesis.
                                                                                     (f) For non-fixed equipment, on the
                                                                                      outside of the product: ``WARNING--
                                                                                      Risk of Fire or Explosion--Store in a
                                                                                      well-ventilated room without
                                                                                      continuously operating flames or other
                                                                                      potential ignition.''
                                                                                     (g) All of these markings must be in
                                                                                      letters no less than 6.4 mm (\1/4\
                                                                                      inch) high.
                                                                                     The equipment must have red
                                                                                      Pantone[supreg] Matching System (PMS)
                                                                                      #185 or RAL 3020 marked service ports,
                                                                                      pipes, hoses, or other devices through
                                                                                      which the refrigerant passes, to
                                                                                      indicate the use of a flammable
                                                                                      refrigerant. This color must be
                                                                                      applied at all service ports and other
                                                                                      parts of the system where service
                                                                                      puncturing or other actions creating
                                                                                      an opening from the refrigerant
                                                                                      circuit to the atmosphere might be
                                                                                      expected and must extend a minimum of
                                                                                      one (1) inch (25 mm) in both
                                                                                      directions from such locations and
                                                                                      shall be replaced if removed.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR part 51). You may inspect a copy at the
  U.S. EPA or at the National Archives and Records Administration (NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301
  Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets, (202) 202-1744. For information on the availability of this material at NARA, visit
  www.archives.gov/federal-register/cfr/ibr-locations.html or email [email protected].
\2\ You may obtain the material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern Avenue; Bensenville, IL 60106; email: 2000.com">[email protected]2000.com; phone: 1-888-853-3503 in the U.S. or Canada (other countries +1-415-352-2168); website: https://ulstandards.ul.com/ or www.comm-2000.com.
\3\ UL 471. Commercial Refrigerators and Freezers. 10th edition. Supplement SB: Requirements for Refrigerators and Freezers Employing a Flammable
  Refrigerant in the Refrigerating System. November 24, 2010.
\4\ UL 484. Room Air Conditioners. 8th edition. Supplement SA: Requirements for Room Air Conditioners Employing a Flammable Refrigerant in the
  Refrigerating System and Appendices B through F. December 21, 2007, with changes through August 3, 2012.
\5\ UL 541. Refrigerated Vending Machines. 7th edition. Supplement SA: Requirements for Refrigerated Venders Employing a Flammable Refrigerant in the
  Refrigerating System. December 30, 2011.
\6\ UL 60335-2-24. Standard for Safety: Requirements for Household and Similar Electrical Appliances--Safety--Part 2-24: Particular Requirements for
  Refrigerating Appliances, Ice-Cream Appliances and Ice-Makers, Second edition, dated April 28, 2017.
\7\ UL 60335-2-40, Standard for Safety: Household And Similar Electrical Appliances--Safety--Part 2-40: Particular Requirements for Electrical Heat
  Pumps, Air-Conditioners and Dehumidifiers, 3rd edition, Dated November 1, 2019.


[[Page 26424]]

* * * * *

0
3. Add appendix X to subpart G of part 82 to read as follows:

Appendix X to Subpart G of Part 82--Substitutes Listed in the April 28, 
2023 Final Rule--Effective May 30, 2023

                       Refrigerants--Substitutes Acceptable Subject to Narrowed Use Limits
----------------------------------------------------------------------------------------------------------------
            End-use                Substitute         Decision       Narrowed use limits    Further information
----------------------------------------------------------------------------------------------------------------
1. Very low temperature         R-1150..........  Acceptable         Temperature
 refrigeration (new only).                         Subject to Use    range--R-1150 may
                                                   Conditions and    only be used in
                                                   Narrowed Use      equipment designed
                                                   Limits.           specifically to
                                                                     reach temperatures
                                                                     lower than -80
                                                                     [deg]C (-112 [deg]F).
                                                                     The
                                                                     manufacturers of new
                                                                     very low temperature
                                                                     equipment need to
                                                                     demonstrate that
                                                                     other alternatives
                                                                     are not technically
                                                                     feasible. They must
                                                                     document the results
                                                                     of their evaluation
                                                                     that showed the
                                                                     other alternatives
                                                                     to be not
                                                                     technically feasible
                                                                     and maintain that
                                                                     documentation in
                                                                     their files. This
                                                                     documentation, which
                                                                     does not need to be
                                                                     submitted to EPA
                                                                     unless requested to
                                                                     demonstrate
                                                                     compliance, ``shall
                                                                     include descriptions
                                                                     of substitutes
                                                                     examined and
                                                                     rejected, processes
                                                                     or products in which
                                                                     the substitute is
                                                                     needed, reason for
                                                                     rejection of other
                                                                     alternatives, e.g.,
                                                                     performance,
                                                                     technical or safety
                                                                     standards, and the
                                                                     anticipated date
                                                                     other substitutes
                                                                     will be available
                                                                     and projected time
                                                                     for switching to
                                                                     other available
                                                                     substitutes.'' (40
                                                                     CFR 82.180(b)(3)).
----------------------------------------------------------------------------------------------------------------


                                             Refrigerants--Substitutes Acceptable Subject to Use Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
              End-use                      Substitute               Decision                      Use conditions                  Further information
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Centrifugal Chillers for comfort  HFC-32, HFO-1234yf, R-  Acceptable Subject to   These refrigerants may be used only in   Applicable OSHA
 cooling and Industrial Process Air   452B, R-454A, R-454B,   Use Conditions.         new equipment specifically designed      requirements at 29 CFR
 Conditioning.                        R-454C.                                         and clearly identified for the           part 1910 must be
                                                                                      refrigerant (i.e., none of these         followed, including those
                                                                                      substitutes may be used as a             at 29 CFR 1910.94
Positive Displacement Chillers for                                                    conversion or ``retrofit'' refrigerant   (ventilation) and
 comfort cooling and Industrial                                                       for existing equipment designed for      1910.106 (flammable and
 Process Air Conditioning.                                                            other refrigerants).                     combustible liquids),
                                                                                     These substitutes may only be used in     1910.110 (storage and
                                                                                      air conditioning equipment that meets    handling of liquefied
                                                                                      all requirements in UL 60335-2-40.1 3    petroleum gases), and
                                                                                      5 In cases where this listing 1          1910.1000 (toxic and
                                                                                      includes requirements more stringent     hazardous substances).
                                                                                      than those of UL 60335-2-40, the        Proper ventilation should
                                                                                      appliance must meet the requirements     be maintained at all
                                                                                      of this listing 1 in place of the        times during the
                                                                                      requirements in the UL 60335-2-40.       manufacture and storage
                                                                                     These refrigerants may be used in         of equipment containing
                                                                                      chillers if and only if such chiller     flammable refrigerants
                                                                                      meets all requirements listed in         through adherence to good
                                                                                      ASHRAE 15-2019.1 2 4 In cases where      manufacturing practices
                                                                                      this listing 1 includes requirements     as per 29 CFR 1910.106.
                                                                                      different than those of ASHRAE 15-       If refrigerant levels in
                                                                                      2019, the appliance must meet the        the air surrounding the
                                                                                      requirements of this listing 1 in        equipment rise above one-
                                                                                      place of the requirements in ASHRAE 15-  fourth of the lower
                                                                                      2019. Where similar requirements of      flammability limit, the
                                                                                      ASHRAE 15-2019 and UL 60335-2-40         space should be
                                                                                      differ, the more stringent or            evacuated, and reentry
                                                                                      conservative condition shall apply       should occur only after
                                                                                      unless superseded by this listing 1.     the space has been
                                                                                     The following markings must be attached   properly ventilated.
                                                                                      at the locations provided and must be   Technicians and equipment
                                                                                      permanent:                               manufacturers should wear
                                                                                     (a) On the outside of the equipment:      appropriate personal
                                                                                      ``WARNING--Risk of Fire. Flammable       protective equipment,
                                                                                      Refrigerant Used. To Be Repaired Only    including chemical
                                                                                      By Trained Service Personnel, Do Not     goggles and protective
                                                                                      Puncture Refrigerant Tubing.''           gloves, when handling
                                                                                     (b) On the outside of the equipment:      flammable refrigerants.
                                                                                      ``WARNING--Risk of Fire. Dispose of      Special care should be
                                                                                      Properly In Accordance With Federal Or   taken to avoid contact
                                                                                      Local Regulations. Flammable             with the skin which, like
                                                                                      Refrigerant Used.''                      many refrigerants, can
                                                                                                                               cause freeze burns on the
                                                                                                                               skin.
                                                                                                                              A class B dry powder type
                                                                                                                               fire extinguisher should
                                                                                                                               be kept nearby.
                                                                                                                              Technicians should only
                                                                                                                               use spark-proof tools
                                                                                                                               when working on air
                                                                                                                               conditioning equipment
                                                                                                                               with flammable
                                                                                                                               refrigerants.
                                                                                                                              Any recovery equipment
                                                                                                                               used should be designed
                                                                                                                               for flammable
                                                                                                                               refrigerants. Only
                                                                                                                               technicians specifically
                                                                                                                               trained in handling
                                                                                                                               flammable refrigerants
                                                                                                                               should service
                                                                                                                               refrigeration equipment
                                                                                                                               containing this
                                                                                                                               refrigerant. Technicians
                                                                                                                               should gain an
                                                                                                                               understanding of
                                                                                                                               minimizing the risk of
                                                                                                                               fire and the steps to use
                                                                                                                               flammable refrigerants
                                                                                                                               safely.

[[Page 26425]]

 
                                                                                        (c) On the inside of the equipment    Room occupants should
                                                                                         near the compressor: ``WARNING--      evacuate the space
                                                                                         Risk of Fire. Flammable Refrigerant   immediately following the
                                                                                         Used. Consult Repair Manual/Owner's   accidental release of
                                                                                         Guide Before Attempting to Service    this refrigerant.
                                                                                         This Product. All Safety             Personnel commissioning,
                                                                                         Precautions Must be Followed.''       maintaining, repairing,
                                                                                     (d) For any equipment pre-charged at      decommissioning and
                                                                                      the factory, on the equipment            disposing of appliances
                                                                                      packaging or on the outside of the       with this refrigerant
                                                                                      equipment: ``WARNING--Risk of Fire due   should obtain training
                                                                                      to Flammable Refrigerant Used. Follow    and follow practices
                                                                                      Handling Instructions Carefully in       consistent with Annex HH
                                                                                      Compliance with National Regulations''   of UL 60335-2-40, 3rd
                                                                                     a. If the equipment is delivered          edition.3 5
                                                                                      packaged, this label shall be applied   CAA section 608(c)(2)
                                                                                      on the packaging.                        prohibits knowingly
                                                                                     b. If the equipment is not delivered      venting or otherwise
                                                                                      packaged, this label shall be applied    knowingly releasing or
                                                                                      on the outside of the equipment near     disposing of substitute
                                                                                      the control panel or nameplate.          refrigerants in the
                                                                                     (e) On the equipment near the             course of maintaining,
                                                                                      nameplate:                               servicing, repairing or
                                                                                     a. At the top of the marking: ``Minimum   disposing of an appliance
                                                                                      Installation Height, X m (W ft).''       or industrial process
                                                                                      This marking is only required if         refrigeration.
                                                                                      required by UL 60335-2-40. The terms    Department of
                                                                                      ``X'' and ``W'' shall be replaced by     Transportation
                                                                                      the numeric height as calculated per     requirements for
                                                                                      UL 60335-2-40. Note that the             transport of flammable
                                                                                      formatting here is slightly different    gases must be followed.
                                                                                      than UL 60335-2-40; specifically, the   Flammable refrigerants
                                                                                      height in Inch-Pound units is placed     being recovered or
                                                                                      in parentheses and the word ``and''      otherwise disposed of
                                                                                      has been replaced by the opening         from residential and
                                                                                      parenthesis.                             light commercial air
                                                                                                                               conditioning appliances
                                                                                                                               are likely to be
                                                                                                                               hazardous waste under the
                                                                                                                               Resource Conservation and
                                                                                                                               Recovery Act (RCRA) (see
                                                                                                                               40 CFR parts 260 through
                                                                                                                               270).
                                                                                          b. Immediately below marking (a)
                                                                                           of this listing 1or at the top of
                                                                                           the marking if marking (a) is not
                                                                                           required: ``Minimum room area
                                                                                           (operating or storage), Y m\2\ (Z
                                                                                           ft\2\).'' The terms ``Y'' and
                                                                                           ``Z'' shall be replaced by the
                                                                                           numeric area as calculated per UL
                                                                                           60335-2-40. Note that the
                                                                                           formatting here is slightly
                                                                                           different than UL 60335-2-40;
                                                                                           specifically, the area in Inch-
                                                                                           Pound units is placed in
                                                                                           parentheses and the word ``and''
                                                                                           has been replaced by the opening
                                                                                           parenthesis.
                                                                                     (f) For non-fixed equipment, on the
                                                                                      outside of the product: ``WARNING--
                                                                                      Risk of Fire or Explosion--Store in a
                                                                                      well-ventilated room without
                                                                                      continuously operating flames or other
                                                                                      potential ignition.''
                                                                                     (g) For fixed equipment that is ducted,
                                                                                      near the nameplate: ``WARNING--Risk of
                                                                                      Fire--Auxiliary devices which may be
                                                                                      ignition sources shall not be
                                                                                      installed in the ductwork, other than
                                                                                      auxiliary devices listed for use with
                                                                                      the specific appliance. See
                                                                                      instructions.''
                                                                                     (h) All of these markings must be in
                                                                                      letters no less than 6.4 mm (\1/4\
                                                                                      inch) high.
                                                                                     The equipment must have red
                                                                                      Pantone[supreg] Matching System (PMS)
                                                                                      #185 or RAL 3020 marked service ports,
                                                                                      pipes, hoses, or other devices through
                                                                                      which the refrigerant passes, to
                                                                                      indicate the use of a flammable
                                                                                      refrigerant. This color must be
                                                                                      applied at all service ports and other
                                                                                      parts of the system where service
                                                                                      puncturing or other actions creating
                                                                                      an opening from the refrigerant
                                                                                      circuit to the atmosphere might be
                                                                                      expected and must extend a minimum of
                                                                                      one (1) inch (25 mm) in both
                                                                                      directions from such locations and
                                                                                      shall be replaced if removed.

[[Page 26426]]

 
2. Residential Dehumidifiers.......  HFO-1234yf, HFC-32, R-  Acceptable Subject to   These refrigerants may be used only in   Applicable OSHA
                                      452B, R-454A, R-454B,   Use Conditions.         new equipment specifically designed      requirements at 29 CFR
                                      and R-454C.                                     and clearly identified for the           part 1910 must be
                                                                                      refrigerant (i.e., none of these         followed, including those
                                                                                      substitutes may be used as a             at 29 CFR 1910.94
                                                                                      conversion or ``retrofit'' refrigerant   (ventilation) and
                                                                                      for existing equipment designed for      1910.106 (flammable and
                                                                                      other refrigerants).                     combustible liquids),
                                                                                     These substitutes may only be used in     1910.110 (storage and
                                                                                      dehumidifier equipment that meets all    handling of liquefied
                                                                                      requirements in UL 60335-2-40.1 3 5 In   petroleum gases), and
                                                                                      cases where this listing 2 includes      1910.1000 (toxic and
                                                                                      requirements more stringent than those   hazardous substances).
                                                                                      of UL 60335-2-40, the appliance must    Proper ventilation should
                                                                                      meet the requirements of this listing    be maintained at all
                                                                                      2 in place of the requirements in UL     times during the
                                                                                      60335-2-40.                              manufacture and storage
                                                                                     The following markings must be attached   of equipment containing
                                                                                      at the locations provided and must be    flammable refrigerants
                                                                                      permanent:                               through adherence to good
                                                                                     (a) On the outside of the equipment:      manufacturing practices
                                                                                      ``WARNING--Risk of Fire. Flammable       as per 29 CFR 1910.106.
                                                                                      Refrigerant Used. To Be Repaired Only    If refrigerant levels in
                                                                                      By Trained Service Personnel. Do Not     the air surrounding the
                                                                                      Puncture Refrigerant Tubing.''           equipment rise above one-
                                                                                     (b) On the outside of the equipment:      fourth of the lower
                                                                                      ``WARNING--Risk of Fire. Dispose of      flammability limit, the
                                                                                      Properly In Accordance With Federal Or   space should be
                                                                                      Local Regulations. Flammable             evacuated, and reentry
                                                                                      Refrigerant Used.''                      should occur only after
                                                                                     (c) On the inside of the equipment near   the space has been
                                                                                      the compressor: ``WARNING--Risk of       properly ventilated.
                                                                                      Fire. Flammable Refrigerant Used.       Technicians and equipment
                                                                                      Consult Repair Manual/Owner's Guide      manufacturers should wear
                                                                                      Before Attempting to Service This        appropriate personal
                                                                                      Product. All Safety Precautions Must     protective equipment,
                                                                                      be Followed.''                           including chemical
                                                                                     (d) For any equipment pre-charged at      goggles and protective
                                                                                      the factory, on the equipment            gloves, when handling
                                                                                      packaging or on the outside of the       flammable refrigerants.
                                                                                      equipment: ``WARNING--Risk of Fire due   Special care should be
                                                                                      to Flammable Refrigerant Used. Follow    taken to avoid contact
                                                                                      Handling Instructions Carefully in       with the skin which, like
                                                                                      Compliance with National Regulations''   many refrigerants, can
                                                                                     a. If the equipment is delivered          cause freeze burns on the
                                                                                      packaged, this label shall be applied    skin.
                                                                                      on the packaging.                       A class B dry powder type
                                                                                     b. If the equipment is not delivered      fire extinguisher should
                                                                                      packaged, this label shall be applied    be kept nearby.
                                                                                      on the outside of the equipment near    Technicians should only
                                                                                      the control panel or nameplate.          use spark-proof tools
                                                                                                                               when working on air
                                                                                                                               conditioning equipment
                                                                                                                               with flammable
                                                                                                                               refrigerants.
                                                                                                                              Any recovery equipment
                                                                                                                               used should be designed
                                                                                                                               for flammable
                                                                                                                               refrigerants. Only
                                                                                                                               technicians specifically
                                                                                                                               trained in handling
                                                                                                                               flammable refrigerants
                                                                                                                               should service
                                                                                                                               refrigeration equipment
                                                                                                                               containing this
                                                                                                                               refrigerant. Technicians
                                                                                                                               should gain an
                                                                                                                               understanding of
                                                                                                                               minimizing the risk of
                                                                                                                               fire and the steps to use
                                                                                                                               flammable refrigerants
                                                                                                                               safely.
                                                                                                                              Room occupants should
                                                                                                                               evacuate the space
                                                                                                                               immediately following the
                                                                                                                               accidental release of
                                                                                                                               this refrigerant.
                                                                                                                              Personnel commissioning,
                                                                                                                               maintaining, repairing,
                                                                                                                               decommissioning and
                                                                                                                               disposing of appliances
                                                                                                                               with this refrigerant
                                                                                                                               should obtain training
                                                                                                                               and follow practices
                                                                                                                               consistent with Annex HH
                                                                                                                               of UL 60335-2-40.3 5
                                                                                        (e) On the equipment near the         CAA section 608(c)(2)
                                                                                         nameplate:                            prohibits knowingly
                                                                                     a. At the top of the marking: ``Minimum   venting or otherwise
                                                                                      Installation Height, X m (W ft).''       knowingly releasing or
                                                                                      This marking is only required if         disposing of substitute
                                                                                      required by UL 60335-2-40. The terms     refrigerants in the
                                                                                      ``X'' and ``W'' shall be replaced by     course of maintaining,
                                                                                      the numeric height as calculated per     servicing, repairing or
                                                                                      UL 60335-2-40. Note that the             disposing of an appliance
                                                                                      formatting here is slightly different    or industrial process
                                                                                      than UL 60335-2-40; specifically, the    refrigeration.
                                                                                      height in Inch-Pound units is placed    Department of
                                                                                      in parentheses and the word ``and''      Transportation
                                                                                      has been replaced by the opening         requirements for
                                                                                      parenthesis.                             transport of flammable
                                                                                                                               gases must be followed.
                                                                                                                              Flammable refrigerants
                                                                                                                               being recovered or
                                                                                                                               otherwise disposed of
                                                                                                                               from residential and
                                                                                                                               light commercial air
                                                                                                                               conditioning appliances
                                                                                                                               are likely to be
                                                                                                                               hazardous waste under the
                                                                                                                               Resource Conservation and
                                                                                                                               Recovery Act (RCRA) (see
                                                                                                                               40 CFR parts 260 through
                                                                                                                               270).
                                                                                          b. Immediately below marking (a)
                                                                                           of this listing 2 or at the top
                                                                                           of the marking if marking (a) is
                                                                                           not required: ``Minimum room area
                                                                                           (operating or storage), Y m\2\ (Z
                                                                                           ft\2\).'' The terms ``Y'' and
                                                                                           ``Z'' shall be replaced by the
                                                                                           numeric area as calculated per UL
                                                                                           60335-2-40. Note that the
                                                                                           formatting here is slightly
                                                                                           different than UL 60335-2-40;
                                                                                           specifically, the area in Inch-
                                                                                           Pound units is placed in
                                                                                           parentheses and the word ``and''
                                                                                           has been replaced by the opening
                                                                                           parenthesis.
                                                                                     (f) On the outside of the product:
                                                                                      ``WARNING--Risk of Fire or Explosion--
                                                                                      Store in a well-ventilated room
                                                                                      without continuously operating flames
                                                                                      or other potential ignition.''
                                                                                     (g) All of these markings must be in
                                                                                      letters no less than 6.4 mm (\1/4\
                                                                                      inch) high.
                                                                                     The equipment must have red
                                                                                      Pantone[supreg] Matching System (PMS)
                                                                                      #185 or RAL 3020 marked service ports,
                                                                                      pipes, hoses, or other devices through
                                                                                      which the refrigerant passes, to
                                                                                      indicate the use of a flammable
                                                                                      refrigerant. This color must be
                                                                                      applied at all service ports and other
                                                                                      parts of the system where service
                                                                                      puncturing or other actions creating
                                                                                      an opening from the refrigerant
                                                                                      circuit to the atmosphere might be
                                                                                      expected and must extend a minimum of
                                                                                      one (1) inch (25 mm) in both
                                                                                      directions from such locations and
                                                                                      shall be replaced if removed.

[[Page 26427]]

 
3. Very Low Temperature              R-1150................  Acceptable Subject to   R-1150 may be used only in new           Applicable OSHA
 Refrigeration.                                               Use Conditions.         equipment specifically designed and      requirements at 29 CFR
                                                                                      clearly identified for the refrigerant   part 1910 must be
                                                                                      (i.e., none of these substitutes may     followed, including those
                                                                                      be used as a conversion or               at 29 CFR 1910.94
                                                                                      ``retrofit'' refrigerant for existing    (ventilation) and
                                                                                      equipment designed for other             1910.106 (flammable and
                                                                                      refrigerants).                           combustible liquids),
                                                                                     R-1150 may only be used in laboratory     1910.110 (storage and
                                                                                      equipment that meet all requirements     handling of liquefied
                                                                                      in UL 61010-2-011.1 3 6 In cases where   petroleum gases), and
                                                                                      this listing 3 includes requirements     1910.1000 (toxic and
                                                                                      more stringent than those of UL 61010-   hazardous substances).
                                                                                      2-011, the appliance must meet the      Proper ventilation should
                                                                                      requirements of this listing 3 in        be maintained at all
                                                                                      place of the requirements in UL 61010-   times during the
                                                                                      2-011.                                   manufacture and storage
                                                                                     Requirements of note include:             of equipment containing
                                                                                     (a) Warning labels--The following         flammable refrigerants
                                                                                      markings, or the equivalent, must be     through adherence to good
                                                                                      provided in letters no less than 6.4     manufacturing practices
                                                                                      mm (\1/4\ inch) high and must be         as per 29 CFR 1910.106.
                                                                                      permanent:                               If refrigerant levels in
                                                                                     (b) Attach near the machine               the air surrounding the
                                                                                      compartment: ``DANGER--Risk of Fire or   equipment rise above one-
                                                                                      Explosion. Flammable Refrigerant Used.   fourth of the lower
                                                                                      To Be Repaired Only By Trained Service   flammability limit, the
                                                                                      Personnel. Do Not Puncture Refrigerant   space should be
                                                                                      Tubing''                                 evacuated, and reentry
                                                                                                                               should occur only after
                                                                                                                               the space has been
                                                                                                                               properly ventilated.
                                                                                                                              Technicians and equipment
                                                                                                                               manufacturers should wear
                                                                                                                               appropriate personal
                                                                                                                               protective equipment,
                                                                                                                               including chemical
                                                                                                                               goggles and protective
                                                                                                                               gloves, when handling
                                                                                                                               flammable refrigerants.
                                                                                                                               Special care should be
                                                                                                                               taken to avoid contact
                                                                                                                               with the skin which, like
                                                                                                                               many refrigerants, can
                                                                                                                               cause freeze burns on the
                                                                                                                               skin.
                                                                                        (c) Attach near the machine           A class B dry powder type
                                                                                         compartment: ``CAUTION--Risk of       fire extinguisher should
                                                                                         Fire or Explosion. Flammable          be kept nearby.
                                                                                         Refrigerant Used. Consult Repair     Technicians should only
                                                                                         Manual/Owner's Guide Before           use spark-proof tools
                                                                                         Attempting To Service This Product.   when working on air
                                                                                         All Safety Precautions Must be        conditioning equipment
                                                                                         Followed.''                           with flammable
                                                                                     (d) Attach on the exterior of the         refrigerants.
                                                                                      refrigeration equipment: ``CAUTION--    Any recovery equipment
                                                                                      Risk of Fire or Explosion. Dispose of    used should be designed
                                                                                      Properly In Accordance With Federal Or   for flammable
                                                                                      Local Regulations. Flammable             refrigerants. Only
                                                                                      Refrigerant Used.''                      technicians specifically
                                                                                     (e) Attach near all exposed refrigerant   trained in handling
                                                                                      tubing: ``CAUTION--Risk of Fire or       flammable refrigerants
                                                                                      Explosion Due To Puncture Of             should service
                                                                                      Refrigerant Tubing; Follow Handling      refrigeration equipment
                                                                                      Instructions Carefully. Flammable        containing this
                                                                                      Refrigerant Used.''                      refrigerant. Technicians
                                                                                     (f) Attach on the exterior of the         should gain an
                                                                                      refrigeration equipment: ``This          understanding of
                                                                                      equipment is intended for use in         minimizing the risk of
                                                                                      commercial, industrial, or               fire and the steps to use
                                                                                      institutional occupancies as defined     flammable refrigerants
                                                                                      in the Safety Standard for               safely.
                                                                                      Refrigeration Systems, ANSI/ASHRAE      Room occupants should
                                                                                      15.''                                    evacuate the space
                                                                                     (g) Attach on the exterior of the         immediately following the
                                                                                      shipping carton: ``CAUTION--Risk of      accidental release of
                                                                                      Fire or Explosion. Dispose of Properly   this refrigerant.
                                                                                      In Accordance With Federal Or Local     Personnel commissioning,
                                                                                      Regulations.''                           maintaining, repairing,
                                                                                     (h) The instructions shall include the    decommissioning and
                                                                                      following warnings as necessary:         disposing of appliances
                                                                                     a. ``WARNING: Ensure all ventilation      with this refrigerant
                                                                                      openings are not obstructed.''           should obtain training
                                                                                     b. ``WARNING: Do not use mechanical       and follow practices
                                                                                      devices or other means to accelerate     consistent with Annex HH
                                                                                      the defrosting process, other than       of UL 60335-2-40.3 5
                                                                                      those recommended by the                CAA section 608(c)(2)
                                                                                      manufacturer.''                          prohibits knowingly
                                                                                     c. ``WARNING: Do not damage the           venting or otherwise
                                                                                      refrigerant circuit.''                   knowingly releasing or
                                                                                     Equipment must have distinguishing red    disposing of substitute
                                                                                      (Pantone[supreg] Matching System (PMS)   refrigerants in the
                                                                                      #185 or RAL 3020) color-coded hoses      course of maintaining,
                                                                                      and piping to indicate use of a          servicing, repairing or
                                                                                      flammable refrigerant. The laboratory    disposing of an appliance
                                                                                      equipment shall have marked service      or industrial process
                                                                                      ports, pipes, hoses and other devices    refrigeration.
                                                                                      through which the refrigerant is        Department of
                                                                                      serviced. Markings shall extend at       Transportation
                                                                                      least 1 inch (25 mm) from the            requirements for
                                                                                      servicing port and shall be replaced     transport of flammable
                                                                                      if removed.                              gases must be followed.
                                                                                     Equipment must use no more than 150 g    Flammable refrigerants
                                                                                      of R-1150 in each refrigerant circuit    being recovered or
                                                                                      using this refrigerant.                  otherwise disposed of
                                                                                                                               from residential and
                                                                                                                               light commercial air
                                                                                                                               conditioning appliances
                                                                                                                               are likely to be
                                                                                                                               hazardous waste under the
                                                                                                                               Resource Conservation and
                                                                                                                               Recovery Act (RCRA) (see
                                                                                                                               40 CFR parts 260 through
                                                                                                                               270).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR part 51). You may inspect a copy at the
  U.S. EPA or at the National Archives and Records Administration (NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301
  Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets, (202) 202-1744. For information on the availability of this material at NARA, visit
  www.archives.gov/federal-register/cfr/ibr-locations.html or email [email protected].
\2\ You may obtain this material from: American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), 180 Technology Parkway NW,
  Peachtree Corners, Georgia 30092; phone: 404-636-8400; website: www.ashrae.org.
\3\ You may obtain this material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern Avenue, Bensenville, IL 60106; phone: 415-352-2168;
  email: 2000.com">[email protected]2000.com; website: https://ulstandards.ul.com/ or www.comm-2000.com.
\4\ ANSI/ASHRAE Standard 15-2019. Safety Standard for Refrigeration Systems, Copyright 2019, including the following addenda to ANSI/ASHRAE Standard 15-
  2019, Safety Standard for Refrigeration Systems:
 Addendum a, ANSI--approved February 6, 2020.
 Addendum b, ANSI--approved February 6, 2020.
 Addendum c, ANSI--approved September 1, 2020.
 Addendum d, ANSI--approved April 29, 2022.
 Addendum e, ANSI--approved January 27, 2022.
 Addendum f, ANSI--approved September 30, 2020.
 Addendum i, ANSI--approved July 31, 2020.
 Addendum j, ANSI--approved October 30, 2020.
 Addendum k, ANSI--approved October 30, 2020.
 Addendum m, ANSI--approved June 30, 2022.
 Addendum n, ANSI--approved May 31, 2022.

[[Page 26428]]

 
 Addendum o, ANSI--approved April 29, 2022.
 Addendum q, ANSI--approved May 31, 2022.
 Addendum r, ANSI--approved May 31, 2022.
\5\ UL 60335-2-40, Standard for Safety: Household And Similar Electrical Appliances--Safety--Part 2-40: Particular Requirements for Electrical Heat
  Pumps, Air-Conditioners and Dehumidifiers, 3rd edition, Dated November 1, 2019.
\6\ UL 61010-2-011, Standard for Safety: Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory Use--Part 011: Particular
  Requirements for Refrigerating Equipment, 2nd edition, Dated May 13, 2021.


             Fire Suppression and Explosion Protection Agents--Acceptable Subject to Use Conditions
----------------------------------------------------------------------------------------------------------------
            End-use                Substitute         Decision          Use conditions      Further information
----------------------------------------------------------------------------------------------------------------
1. Total Flooding.............  2-BTP...........  Acceptable        Acceptable only for    This fire suppressant
                                                   Subject to Use    use in normally        has a relatively low
                                                   Conditions.       unoccupied spaces      GWP of 0.23-0.26 and
                                                                     under 500 ft\3\.       a short atmospheric
                                                                                            lifetime of
                                                                                            approximately seven
                                                                                            days.
                                                                                           This agent is subject
                                                                                            to a TSCA section
                                                                                            5(a)(2) SNUR.
                                                                                           For establishments
                                                                                            manufacturing,
                                                                                            installing and
                                                                                            maintaining
                                                                                            equipment using this
                                                                                            agent, EPA
                                                                                            recommends the
                                                                                            following:
                                                                                            This agent
                                                                                            should be used in
                                                                                            accordance with the
                                                                                            safety guidelines in
                                                                                            the latest edition
                                                                                            of NFPA 2001,
                                                                                            Standard on Clean
                                                                                            Agent Fire
                                                                                            Extinguishing
                                                                                            Systems; \1\
                                                                                            In the case
                                                                                            that 2-BTP is
                                                                                            inhaled, person(s)
                                                                                            should be
                                                                                            immediately removed
                                                                                            and exposed to fresh
                                                                                            air; if breathing is
                                                                                            difficult, person(s)
                                                                                            should seek medical
                                                                                            attention;
                                                                                            Eye wash and
                                                                                            quick drench
                                                                                            facilities should be
                                                                                            available. In case
                                                                                            of ocular exposure,
                                                                                            person(s) should
                                                                                            immediately flush
                                                                                            the eyes, including
                                                                                            under the eyelids,
                                                                                            with fresh water and
                                                                                            move to a non-
                                                                                            contaminated area;
                                                                                            Exposed
                                                                                            persons should
                                                                                            remove all
                                                                                            contaminated
                                                                                            clothing and
                                                                                            footwear to avoid
                                                                                            irritation; and
                                                                                            medical attention
                                                                                            should be sought if
                                                                                            irritation develops
                                                                                            or persists;
                                                                                            Although
                                                                                            unlikely, in case of
                                                                                            ingestion of 2-BTP,
                                                                                            the person(s) should
                                                                                            consult a physician
                                                                                            immediately;
                                                                                           
                                                                                            Manufacturing space
                                                                                            should be equipped
                                                                                            with specialized
                                                                                            engineering controls
                                                                                            and well ventilated
                                                                                            with a local exhaust
                                                                                            system and low-lying
                                                                                            source ventilation
                                                                                            to effectively
                                                                                            mitigate potential
                                                                                            occupational
                                                                                            exposure; regular
                                                                                            testing and
                                                                                            monitoring of the
                                                                                            workplace atmosphere
                                                                                            should be conducted;
                                                                                            Employees
                                                                                            responsible for
                                                                                            chemical processing
                                                                                            should wear the
                                                                                            appropriate PPE,
                                                                                            such as protective
                                                                                            gloves, tightly
                                                                                            sealed goggles,
                                                                                            protective work
                                                                                            clothing, and
                                                                                            suitable respiratory
                                                                                            protection in case
                                                                                            of accidental
                                                                                            release or
                                                                                            insufficient
                                                                                            ventilation;
                                                                                            All spills
                                                                                            should be cleaned up
                                                                                            immediately in
                                                                                            accordance with good
                                                                                            industrial hygiene
                                                                                            practices; and
                                                                                            Training for
                                                                                            safe handling
                                                                                            procedures should be
                                                                                            provided to all
                                                                                            employees that would
                                                                                            be likely to handle
                                                                                            containers of the
                                                                                            agent or
                                                                                            extinguishing units
                                                                                            filled with the
                                                                                            agent.
                                                                                            Safety
                                                                                            features that are
                                                                                            typical of total
                                                                                            flooding systems
                                                                                            such as predischarge
                                                                                            alarms, time delays,
                                                                                            and system abort
                                                                                            switches should be
                                                                                            provided, as
                                                                                            directed by
                                                                                            applicable OSHA
                                                                                            regulations and NFPA
                                                                                            standards.\1\ Use of
                                                                                            this agent should
                                                                                            also conform to
                                                                                            relevant OSHA
                                                                                            requirements,
                                                                                            including 29 CFR
                                                                                            1910.160 and
                                                                                            1910.162.
                                                                                           See notes 1 through 5
                                                                                            to this table.
2. Streaming..................  2-BTP...........  Acceptable,       Acceptable only for    This fire suppressant
                                                   Subject to Use    use in non-            has a relatively low
                                                   Conditions.       residential            GWP of 0.23-0.26 and
                                                                     applications, except   a short atmospheric
                                                                     for commercial home    lifetime of
                                                                     office and personal    approximately seven
                                                                     watercraft.            days.
                                                                                           This agent is subject
                                                                                            to a TSCA section
                                                                                            5(a)(2) SNUR.
                                                                                           For establishments
                                                                                            manufacturing,
                                                                                            installing and
                                                                                            maintaining
                                                                                            equipment using this
                                                                                            agent, EPA
                                                                                            recommends the
                                                                                            following:
                                                                                            This agent
                                                                                            should be used in
                                                                                            accordance with the
                                                                                            safety guidelines in
                                                                                            the latest edition
                                                                                            of NFPA 10, Standard
                                                                                            for Portable Fire
                                                                                            Extinguishers; \1\
                                                                                            In the case
                                                                                            that 2-BTP is
                                                                                            inhaled, person(s)
                                                                                            should be
                                                                                            immediately removed
                                                                                            and exposed to fresh
                                                                                            air; if breathing is
                                                                                            difficult, person(s)
                                                                                            should seek medical
                                                                                            attention;
                                                                                            Eye wash and
                                                                                            quick drench
                                                                                            facilities should be
                                                                                            available. In case
                                                                                            of ocular exposure,
                                                                                            person(s) should
                                                                                            immediately flush
                                                                                            the eyes, including
                                                                                            under the eyelids,
                                                                                            with fresh water and
                                                                                            move to a non-
                                                                                            contaminated area;
                                                                                            Exposed
                                                                                            persons should
                                                                                            remove all
                                                                                            contaminated
                                                                                            clothing and
                                                                                            footwear to avoid
                                                                                            irritation; and
                                                                                            medical attention
                                                                                            should be sought if
                                                                                            irritation develops
                                                                                            or persists;
                                                                                            Although
                                                                                            unlikely, in case of
                                                                                            ingestion of 2-BTP,
                                                                                            the person(s) should
                                                                                            consult a physician
                                                                                            immediately;

[[Page 26429]]

 
                                                                                           
                                                                                            Manufacturing space
                                                                                            should be equipped
                                                                                            with specialized
                                                                                            engineering controls
                                                                                            and well ventilated
                                                                                            with a local exhaust
                                                                                            system and low-lying
                                                                                            source ventilation
                                                                                            to effectively
                                                                                            mitigate potential
                                                                                            occupational
                                                                                            exposure; regular
                                                                                            testing and
                                                                                            monitoring of the
                                                                                            workplace atmosphere
                                                                                            should be conducted;
                                                                                            Employees
                                                                                            responsible for
                                                                                            chemical processing
                                                                                            should wear the
                                                                                            appropriate PPE,
                                                                                            such as protective
                                                                                            gloves, tightly
                                                                                            sealed goggles,
                                                                                            protective work
                                                                                            clothing, and
                                                                                            suitable respiratory
                                                                                            protection in case
                                                                                            of accidental
                                                                                            release or
                                                                                            insufficient
                                                                                            ventilation;
                                                                                            All spills
                                                                                            should be cleaned up
                                                                                            immediately in
                                                                                            accordance with good
                                                                                            industrial hygiene
                                                                                            practices; and
                                                                                            Training for
                                                                                            safe handling
                                                                                            procedures should be
                                                                                            provided to all
                                                                                            employees that would
                                                                                            be likely to handle
                                                                                            containers of the
                                                                                            agent or
                                                                                            extinguishing units
                                                                                            filled with the
                                                                                            agent.
                                                                                           See notes 1 through 5
                                                                                            to this table.
3. Total Flooding.............  EXXFIRE [supreg]  Acceptable        Acceptable only for    Use of this agent
                                                   Subject to Use    use in normally        should be in
                                                   Conditions.       unoccupied spaces.     accordance with the
                                                                                            safety guidelines in
                                                                                            the latest edition
                                                                                            of the NFPA 2001,
                                                                                            Standard on Clean
                                                                                            Agent Fire
                                                                                            Extinguishing
                                                                                            Systems.\1\
                                                                                           For establishments
                                                                                            manufacturing,
                                                                                            installing and
                                                                                            maintaining
                                                                                            equipment using this
                                                                                            agent, EPA
                                                                                            recommends the
                                                                                            following:
                                                                                            In the case
                                                                                            that EXXFIRE
                                                                                            [supreg] is inhaled,
                                                                                            person(s) should be
                                                                                            immediately removed
                                                                                            and exposed to fresh
                                                                                            air.
                                                                                            Eye wash and
                                                                                            quick drench
                                                                                            facilities should be
                                                                                            available. In case
                                                                                            of ocular exposure,
                                                                                            person(s) should
                                                                                            immediately flush
                                                                                            the eyes with water
                                                                                            for a minimum of 15
                                                                                            minutes.
                                                                                            In the case
                                                                                            of dermal exposure,
                                                                                            the SDS recommends
                                                                                            that person(s)
                                                                                            should remove large
                                                                                            grain particles,
                                                                                            rinse with water for
                                                                                            a minimum of 15
                                                                                            minutes, and remove
                                                                                            all contaminated
                                                                                            clothing.
                                                                                           
                                                                                            Manufacturing space
                                                                                            should be equipped
                                                                                            with engineering
                                                                                            controls,
                                                                                            specifically an
                                                                                            adequate exhaust
                                                                                            ventilation system,
                                                                                            to effectively
                                                                                            mitigate potential
                                                                                            occupational
                                                                                            exposure.
                                                                                            Employees
                                                                                            responsible for
                                                                                            chemical processing
                                                                                            should wear the
                                                                                            appropriate
                                                                                            personnel protective
                                                                                            equipment (PPE),
                                                                                            such as protective
                                                                                            gloves, tightly
                                                                                            sealed goggles,
                                                                                            protective work
                                                                                            clothing, and
                                                                                            suitable respiratory
                                                                                            protection in case
                                                                                            of accidental
                                                                                            release or
                                                                                            insufficient
                                                                                            ventilation.
                                                                                            All spills
                                                                                            should be cleaned up
                                                                                            immediately in
                                                                                            accordance with good
                                                                                            industrial hygiene
                                                                                            practices.
                                                                                            Training for
                                                                                            safe handling
                                                                                            procedures should be
                                                                                            provided to all
                                                                                            employees that would
                                                                                            be likely to handle
                                                                                            containers of the
                                                                                            agent or
                                                                                            extinguishing units
                                                                                            filled with the
                                                                                            agent.
                                                                                            Safety
                                                                                            features that are
                                                                                            typical of total
                                                                                            flooding systems
                                                                                            such as predischarge
                                                                                            alarms, time delays,
                                                                                            and system abort
                                                                                            switches should be
                                                                                            provided, as
                                                                                            directed by
                                                                                            applicable OSHA
                                                                                            regulations and NFPA
                                                                                            standards.\1\
                                                                                           See notes 1 through 5
                                                                                            to this table.
4. Total Flooding.............  Powdered Aerosol  Acceptable        Acceptable only for    Use of this agent
                                 H.                Subject to Use    use in normally        should be in
                                                   Conditions.       unoccupied spaces.     accordance with the
                                                                                            safety guidelines in
                                                                                            the latest edition
                                                                                            of NFPA 2010,
                                                                                            Standard for Fixed
                                                                                            Aerosol Fire
                                                                                            Extinguishing
                                                                                            Systems.\1\
                                                                                           For establishments
                                                                                            manufacturing,
                                                                                            installing, and
                                                                                            maintaining
                                                                                            equipment using this
                                                                                            agent, EPA
                                                                                            recommends the
                                                                                            following:
                                                                                            Workers
                                                                                            should use
                                                                                            appropriate safety
                                                                                            and protective
                                                                                            equipment (e.g.,
                                                                                            protective gloves,
                                                                                            tightly sealed
                                                                                            goggles, protective
                                                                                            work clothing, and
                                                                                            particulate-removing
                                                                                            respirators using
                                                                                            NIOSH type N95 or
                                                                                            better filters)
                                                                                            consistent with OSHA
                                                                                            guidelines.
                                                                                            A local
                                                                                            exhaust system
                                                                                            should be installed
                                                                                            and operated to
                                                                                            provide adequate
                                                                                            ventilation to
                                                                                            reduce airborne
                                                                                            exposure to Powdered
                                                                                            Aerosol H
                                                                                            constituents.
                                                                                            An eye wash
                                                                                            fountain and quick
                                                                                            drench facility
                                                                                            should be close to
                                                                                            the production area.
                                                                                            Training for
                                                                                            safe handling
                                                                                            procedures should be
                                                                                            provided to all
                                                                                            employees that would
                                                                                            be likely to handle
                                                                                            the containers of
                                                                                            the agent or
                                                                                            extinguishing units
                                                                                            filled with the
                                                                                            agent.
                                                                                            Workers
                                                                                            responsible for
                                                                                            cleanup should allow
                                                                                            particulates to
                                                                                            settle before
                                                                                            reentering area and
                                                                                            wear appropriate
                                                                                            personal protective
                                                                                            equipment.
                                                                                            All spills
                                                                                            should be cleaned up
                                                                                            immediately in
                                                                                            accordance with good
                                                                                            industrial hygiene
                                                                                            practices.
                                                                                           See notes 1 through 5
                                                                                            to this table.
----------------------------------------------------------------------------------------------------------------
\1\ National Fire Protection Association (NFPA) standards are available from www.nfpa.org.

[[Page 26430]]

 
Note 1: EPA recommends that users consult Section VIII of the OSHA Technical Manual for information on selecting
  the appropriate types of personal protective equipment for all listed fire suppression agents. EPA has no
  intention of duplicating or displacing OSHA coverage related to the use of personal protective equipment
  (e.g., respiratory protection), fire protection, hazard communication, worker training or any other
  occupational safety and health standard with respect to halon substitutes.
Note 2: Use of all listed fire suppression agents should conform to relevant OSHA requirements, including 29 CFR
  1910.160 and 1910.162.
Note 3: Per OSHA requirements, protective gear (SCBA) should be available in the event personnel should reenter
  the area.
Note 4: Discharge testing should be strictly limited to that which is essential to meet safety or performance
  requirements.
Note 5: The agent should be recovered from the fire protection system in conjunction with testing or servicing
  and recycled for later use or destroyed.

[FR Doc. 2023-08663 Filed 4-27-23; 8:45 am]
BILLING CODE 6560-50-P


