Cover Sheet for Transmitting Documents under E.O. 12866

Information about the Regulatory Action Related to This Document

Title of the Regulatory Action:  Protection of Stratospheric Ozone: New
Substitute in the Motor Vehicle Air Conditioning Sector under the
Significant New Alternatives Policy (SNAP) Program

Regulatory Identifier Number (RIN):  2060-AP11

Stage of Action:  Proposal

Information about This Document

Document Creation Date:  June 8, 2009

Document Type:

(X)  	Draft preamble and regulatory text (i.e., this is the regulatory
action)

(  )  	Draft Technical Support Document

(  )  	Draft Regulatory Impact Analyses

(  )  	Draft Information Collection Request

(  )  	Other:  _________________________________________________

  SEQ CHAPTER \h \r 1 ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2008-0664; FRL-XXXX-X] 

RIN 2060-AP11

Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle
Air Conditioning Sector under the Significant New Alternatives Policy
(SNAP) Program

AGENCY:  Environmental Protection Agency (EPA).

ACTION: Proposed Rule.

------------------------------------------------------------------------
---------------------------------------------

SUMMARY:  The Clean Air Act requires the Environmental Protection Agency
(EPA) to review alternatives for ozone-depleting substances and to
approve of substitutes that do not present a risk more significant than
other alternatives that are available. Under that authority, the
Significant New Alternatives Policy (SNAP) program of EPA proposes to
expand the list of acceptable substitutes for ozone-depleting substances
(ODS).  The substitute addressed in this proposal is for the motor
vehicle air conditioning (MVAC) end-use within the refrigeration and
air-conditioning sector.  EPA proposes to find HFO-1234yf acceptable,
subject to use conditions.  The proposed substitute is a non
ozone-depleting gas and consequently does not contribute to
stratospheric ozone depletion.

DATES:  Comments must be received on or before [INSERT 60 DAYS FROM DATE
OF PUBLICATION IN THE FEDERAL REGISTER], unless a public hearing is
requested.  Comments must then be received on or before [INSERT DATE 75
DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER].   Any party requesting
a public hearing must notify the contact listed below under FOR FURTHER
INFORMATION CONTACT by 5 p.m. Eastern Daylight Time on [INSERT DATE 10
DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER.]  If a hearing is held,
it will take place on [INSERT 15 DAYS AFTER PUBLICATION]. 

  SEQ CHAPTER \h \r 1 ADDRESSES:  Submit your comments, identified by
Docket ID No. EPA-HQ-OAR-2008-0664, by one of the following methods:

Federal eRulemaking Portal:     HYPERLINK "http://www.regulations.gov" 
http://www.regulations.gov .  Follow the on-line instructions for
submitting comments.

E-mail:    HYPERLINK "mailto:a-and-r-Docket@epa.gov" 
a-and-r-Docket@epa.gov 

Fax:  (202) 566-1741

Mail: Environmental Protection Agency

EPA Docket Center (EPA/DC)

Mailcode 6102T

      Attention Docket ID No. EPA-HQ-OAR-2008-0664

     1200 Pennsylvania Avenue, NW

     Washington, DC 20460

Hand Delivery: Public Reading Room, Room 3334 

EPA West Building

1301 Constitution Avenue, NW

Washington, DC 

Such deliveries are only accepted during the Docket’s normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.

  SEQ CHAPTER \h \r 1 Instructions:  Direct your comments to Docket ID
No. EPA-HQ-OAR-2008-0664.  EPA's policy is that all comments received
will be included in the public docket without change and may be made
available online at   HYPERLINK "http://www.regulations.gov" 
www.regulations.gov , including any personal information provided,
unless the comment includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to be
CBI or otherwise protected through www.regulations.gov or e-mail.  The  
HYPERLINK "http://www.regulations.gov"  www.regulations.gov  website is
an “anonymous access” system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment.  If you send an e-mail comment directly to EPA without
going through www.regulations.gov your e-mail address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet.  If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit.  If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA may
not be able to consider your comment.  Electronic files should avoid the
use of special characters, any form of encryption, and be free of any
defects or viruses. 

  SEQ CHAPTER \h \r 1 Docket: All documents in the docket are listed in
the   HYPERLINK "http://www.regulations.gov"  www.regulations.gov 
index.  Although listed in the index, some information is not publicly
available, e.g., CBI or other information whose disclosure is restricted
by statute.  Certain other material, such as copyrighted material, will
be publicly available only in hard copy.  Publicly available docket
materials are available either electronically in   HYPERLINK
"http://www.regulations.gov"  www.regulations.gov  or in hard copy at
the Air Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW,
Washington, DC.  This Docket Facility is open from 8:30 a.m. to 4:30
p.m., Monday through Friday, excluding legal holidays.    SEQ CHAPTER \h
\r 1 The telephone number for the Public Reading Room is (202) 566-1744,
and the telephone number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:  For further information about this
proposed rule, contact Karen Thundiyil, Stratospheric Protection
Division, Office of Atmospheric Programs; Environmental Protection
Agency, Mail Code 6205J, 1200 Pennsylvania Avenue NW, Washington DC
20460; telephone number (202) 343-9464, fax number, (202) 343-2342;
email address at thundiyil.karen@epa.gov.  Notices and rulemakings under
the SNAP program are available on EPA’s Stratospheric Ozone web site
at www.epa.gov/ozone/snap/regulations.html.  For copies of the full list
of SNAP decisions in all industrial sectors, contact the EPA
Stratospheric Protection Hotline at (800) 296-1996.  

SUPPLEMENTARY INFORMATION:

	This proposed action, if finalized, would provide motor vehicle
manufacturers and their suppliers an additional refrigerant option for
motor vehicle air conditioning (MVAC) systems. The refrigerant discussed
in this proposed action is a non ozone-depleting substance. 

TABLE OF CONTENTS

  TOC \n \h \z \t "Title 1,2,Title 2,1"    HYPERLINK \l "_Toc232218346" 
I.  Section 612 Statutory and Regulatory Background 

  HYPERLINK \l "_Toc232218347"  A.  Rulemaking 

  HYPERLINK \l "_Toc232218348"  B.  Listing of Unacceptable/Acceptable
Substitutes 

  HYPERLINK \l "_Toc232218349"  C.  Petition Process 

  HYPERLINK \l "_Toc232218350"  D.  90-day Notification 

  HYPERLINK \l "_Toc232218351"  E.  Outreach 

  HYPERLINK \l "_Toc232218352"  F.  Clearinghouse 

  HYPERLINK \l "_Toc232218353"  G. EPA’s Regulations Implementing
Section 612 

  HYPERLINK \l "_Toc232218354"  II.   EPA’s Proposed Decision on
HFO-1234yf 

  HYPERLINK \l "_Toc232218355"  III.   SNAP Criteria for Evaluating
Alternatives 

  HYPERLINK \l "_Toc232218356"  IV.   SNAP Evaluation of HFO-1234yf 

  HYPERLINK \l "_Toc232218357"  A.  Atmospheric Effects and Related
Health and Environmental Impacts 

  HYPERLINK \l "_Toc232218358"  B.  General Population Risks from
Ambient Exposure to Compounds with Direct Toxicity and to Increased
Ground-Level Ozone 

  HYPERLINK \l "_Toc232218359"  C.  Ecosystem Risks 

  HYPERLINK \l "_Toc232218360"  D.  Occupational Risks 

  HYPERLINK \l "_Toc232218361"  E.  Consumer Risks 

  HYPERLINK \l "_Toc232218362"  F.  Flammability 

  HYPERLINK \l "_Toc232218363"  G.  Cost and Availability of the
Substitute 

  HYPERLINK \l "_Toc232218364"  H. Proposed Conclusion on Overall
Impacts on Human Health and the Environment 

  HYPERLINK \l "_Toc232218365"  V.  HFO-1234yf  MVAC System Proposed Use
Conditions 

  HYPERLINK \l "_Toc232218366"  VI. Additional Information Requested 

  HYPERLINK \l "_Toc232218367"  VII. Section 609 Requirements for
HFO-1234yf 

  HYPERLINK \l "_Toc232218368"  VIII.   Statutory and Executive Order
Reviews 

  HYPERLINK \l "_Toc232218369"  A.  Executive Order 12866:  Regulatory
Planning and Review 

  HYPERLINK \l "_Toc232218370"  B.  Paperwork Reduction Act 

  HYPERLINK \l "_Toc232218371"  C.  Regulatory Flexibility Act (RFA) 

  HYPERLINK \l "_Toc232218372"  D.  Unfunded Mandates Reform Act 

  HYPERLINK \l "_Toc232218373"  E.  Executive Order 13132: Federalism 

  HYPERLINK \l "_Toc232218374"  F.   Executive Order 13175: 
Consultation and Coordination with Indian Tribal Governments 

  HYPERLINK \l "_Toc232218375"  G.  Executive Order 13045:  Protection
of Children from Environmental Health and Safety Risks 

  HYPERLINK \l "_Toc232218376"  H.  Executive Order 13211:  Actions that
Significantly Affect Energy Supply, Distribution, or Use 

  HYPERLINK \l "_Toc232218377"  I.  National Technology Transfer and
Advancement Act 

  HYPERLINK \l "_Toc232218378"  J.  Executive Order 12898:  Federal
Actions to Address Environmental Justice in Minority Populations and
Low-Income Populations 

  HYPERLINK \l "_Toc232218379"  IX.   References 

 I.  Section 612 Statutory and Regulatory Background

Section 612 of the Clean Air Act (CAA) requires EPA to develop a program
for evaluating alternatives to ozone-depleting substances.  EPA refers
to this program as the Significant New Alternatives Policy (SNAP)
program.  The major provisions of section 612 and implementing
regulations are: 

A.  Rulemaking

Section 612(c) requires EPA to promulgate rules making it unlawful to
replace any class I (e.g., chlorofluorocarbon, halon, carbon
tetrachloride, methyl chloroform, methyl bromide, and
hydrobromofluorocarbon) or class II (e.g., hydrochlorofluorocarbon)
substance 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.

B.  Listing of Unacceptable/Acceptable Substitutes

Section 612(c) requires EPA to publish a list of the substitutes
unacceptable for specific uses and to publish a corresponding list of
acceptable alternatives for specific uses.  The list of acceptable
substitutes may be found at
http://www.epa.gov/ozone/snap/lists/index.html and the lists of
unacceptable substitutes, acceptable substitutes subject to use
conditions and acceptable substitutes subject to narrowed use limits may
be found at 40 CFR part 82 subpart G.

C.  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).  The Agency has 90 days to grant or deny
a petition.  Where the Agency grants the petition, EPA must publish the
revised lists within an additional six months.

D.  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 new or existing chemicals are introduced into interstate
commerce for significant new uses as substitutes for a class I
substance.  The producer must also provide the Agency with the
producer's unpublished health and safety studies on such substitutes. 

E.  Outreach

Section 612(b)(1) states that the Administrator shall, where
appropriate, seek to maximize the use of federal research facilities and
resources to assist users of class I and II substances in identifying
and developing alternatives to the use of such substances in key
commercial applications.

F.  Clearinghouse

Section 612(b)(4) requires the Agency to maintain a public clearinghouse
of alternative chemicals, product substitutes, and alternative
manufacturing processes that are available for products and
manufacturing processes which use class I and II substances.

G. EPA’s Regulations Implementing Section 612

On March 18, 1994, EPA published the original rulemaking (59 FR 13044)
which established the process for administering the SNAP program and
issued EPA's first lists identifying acceptable and unacceptable
substitutes in the major industrial use sectors.  40 CFR part 82,
subpart G.  These sectors include: refrigeration and air conditioning;
foam blowing; solvents cleaning; fire suppression and explosion
protection; sterilants; aerosols; adhesives, coatings and inks; and
tobacco expansion.  These sectors compose the principal industrial
sectors that historically consumed the largest volumes of ODS.

For the purposes of SNAP, the Agency defines a "substitute" as any
chemical, product substitute, or alternative manufacturing process,
whether existing or new, intended for use as a replacement for a class I
or class II substance in a sector that has historically used ODS. 
Anyone who produces a substitute must provide the Agency with health and
safety studies on the substitute at least 90 days before introducing it
into interstate commerce for significant new use as an alternative.  CAA
section 612(e); 40 CFR 82.176(a).  This requirement applies to
substitute manufacturers, but may include importers, formulators, or
end-users, when they are responsible for introducing a substitute into
commerce.

You can find a complete chronology of SNAP decisions and the appropriate
Federal Register citations at EPA’s Stratospheric Ozone web site at:  
HYPERLINK "http://www.epa.gov/ozone/snap/chron.html." 
www.epa.gov/ozone/snap/chron.html.   This information is also available
from the Air Docket (see Addresses section above for contact
information).

II.   EPA’s Proposed Decision on HFO-1234yf

EPA proposes that hydrofluoroolefin (HFO)-1234yf is acceptable as a
substitute for CFC-12 in new motor vehicle air conditioning systems
(passenger cars and trucks), subject to use conditions.  EPA proposes
the following use conditions:

HFO-1234yf MVAC systems must incorporate engineering strategies and/or
devices so that leaks into the passenger compartment do not result in
HFO-1234yf concentrations at or above the lower flammability limit (LFL)
of 6.2% v/v for more than 15 seconds;

HFO-1234yf MVAC systems must incorporate engineering strategies and/or
devices so that leaks into the engine compartment or vehicle electric
power source storage areas do not result in HFO-1234yf concentrations at
or above the LFL of 6.2% v/v for any period of time;

HFO-1234yf MVAC systems must incorporate protective devices, isolation
and/or ventilation techniques in areas where processes, procedures or
upset conditions such as leaks have the potential to generate HFO-1234yf
concentrations at or above 6.2% v/v in proximity to hybrid/electric
vehicle electric power sources and exhaust manifold surfaces;

HFO-1234yf MVAC systems must use unique fittings to be identified
pursuant to SAE standard J639 and subject to EPA approval;

HFO-1234yf MVAC systems must include a detailed label identifying the
refrigerant and that the refrigerant is flammable; 

HFO-1234yf MVAC systems must have a high-pressure compressor cutoff
switch installed on systems equipped with pressure relief devices; and

Manufacturers must conduct and keep on file Failure Mode and Effect
Analysis (FMEA) on the MVAC as stated in SAE J1739.  

The proposed decision for HFO-1234yf applies to new MVAC systems only in
passenger cars and trucks.  We have previously determined that use of
flammable refrigerants (which would include HFO-1234yf) in existing
equipment as a retrofit is unacceptable (40 CFR part 82, subpart G,
appendix B).  

III.   SNAP Criteria for Evaluating Alternatives 

To determine whether a substitute is acceptable or unacceptable as a
replacement for class I or II compounds, the Agency evaluates
substitutes according to the criteria in §82.180(a)(7).   The Agency
considers, among other things, toxicity, flammability, potential for
occupational and general population exposure, and environmental effects
including ozone depletion potential, atmospheric lifetime, impacts on
local air quality and climate as well as ecosystem effects of the
alternatives.  

This proposal reflects additional information on flammable refrigerants
in MVAC systems that has become available since the HFC-152a September
2006 proposed rule (71 FR 55140) and 2008 final rule (73 FR 33304), as
well as EPA’s latest understanding of all the available information. 
These additional or revised considerations include the increased
proportion of new hybrid and electric vehicle sales in the U.S.,
passenger compartment volume, and improved assumptions for modeling
exercises.  In this rulemaking, HFO-1234yf risks are considered in
relation to the risks associated with HFC-134a and other approved SNAP
MVAC alternatives.  HFC-134a is the predominant ODS refrigerant
substitute used in passenger vehicle MVAC systems.  Other SNAP-approved
MVAC substitutes have not been implemented by car manufacturers or car
air conditioning system manufacturers.  

The EPA’s SNAP program does not require that new substitutes be found
risk-free to be found acceptable.  In reviewing the acceptability of
proposed substitutes, EPA considers how each substitute can be used
within a specific end-use and the resulting risks and uncertainties
surrounding potential health and environmental effects.  

IV.   SNAP Evaluation of HFO-1234yf 

	In the following section, HFO-1234yf is evaluated in terms of the SNAP
criteria defined in §82.180(a)(7).  

A.  Atmospheric Effects and Related Health and Environmental Impacts

HFO-1234yf has an ozone-depletion potential (ODP) of nearly zero
(Papadimitriou, 2007).  By comparison, CFC-12 has an ODP of 1.0 and
HFC-134a has an ODP of 0 (WMO, 2006).  Generally, the other approved
SNAP MVAC substitutes have an ODP of less than 0.2.  

The global warming potential (GWP) of HFO-1234yf is 4, based on a 100
year time horizon (Papadimitriou, 2007), compared to a value of 1 for
carbon dioxide.  For basis of comparison, CFC-12 has a GWP of 10,890 and
HFC-134a has a GWP of 1,430 (WMO, 2006).  The other SNAP-approved MVAC
refrigerants generally have a GWP greater than 1000.  HFO-1234yf has an
atmospheric lifetime of only 11 days (Papadimitriou, 2007), compared to
100 years for CFC-12 and 14.0 years for HFC-134a.  Thus, in terms of
direct refrigerant emissions, HFO-1234yf would have a significantly
smaller impact on climate compared to the ozone depleting substance it
replaces and other common alternatives available in the same end use.

The Agency believes sufficient technical information is available on the
ODP and GWP of HFO-1234yf, but the Agency welcomes additional comment on
the ODP and GWP values described above.  The Agency would give the
greatest weight to peer-reviewed, published papers on HFO-1234yf as
supporting evidence for discussion on ODP and GWP.  

We note that one concern about HFO-1234yf atmospheric effects is
trifluoroacetic acid (CF3COOH, TFA).  TFA is produced from atmospheric
oxidation of HFO-1234yf.  EPA understands that the oxidation of
HFO-1234yf yields >90% TFA, which is significantly higher than the yield
of TFA from HFC-134a and other approved SNAP MVAC substitutes.  TFA is
naturally occurring, but at certain levels is toxic to aquatic life
forms.  

Initial analysis indicates that the projected maximum TFA concentration
in rainwater should not result in a significant risk of aquatic
toxicity.  TFA concentration in rainwater was investigated because it is
difficult to predict what the actual TFA concentrations will be.  This
is because concentrations of environmental contaminants in most fresh
water bodies fluctuate widely due to varying inputs and outputs to most
ponds, lakes, and streams.  Also, use of rainwater TFA concentration as
a point of comparison is more conservative than comparing TFA
concentrations in water bodies because TFA is expected to be diluted in
most freshwater bodies.  The exception to this is vernal pools and
similar seasonal water bodies that have no significant outflow capacity
(ICF, 2009).  

After taking into account the nature of HFO-1234yf degradation and the
resulting TFA concentration in rainwater; regional precipitation
patterns; the geology of closed aquatic systems; and no observed effect
concentrations (NOEC) for TFA, TFA production resulting from HFO-1234yf
emissions is not expected to pose significant harm to aquatic
communities in the near future.  Additional research is necessary to
determine if significant TFA loading is occurring in vernal pools near
major population (ICF, 2009).  EPA is aware of studies to evaluate wet
deposition effects that are underway at the National Institute of
Advanced Industrial Science and Technology (AIST) based in Japan.  Their
results on wet deposition were not available at the time of this
proposal’s drafting, but EPA will consider any relevant findings by
AIST that become available in a final version of this regulation and
will provide an opportunity for additional public comment if the
relevant findings suggest EPA should change its proposed determination. 


Concerns about dry deposition of TFA also exist.  Initial analysis
indicates that it may be somewhat of a concern for photosynthesis (ICF,
2009).  EPA is aware of studies to evaluate dry deposition effects that
are underway at AIST.  Their results on dry deposition were not
available at the time of this proposal’s drafting, but EPA will
consider any relevant findings by AIST that become available in a final
version of this regulation and will provide an opportunity for
additional public comment if the relevant findings suggest EPA should
change its proposed determination.  The AIST findings will be posted in
the docket (EPA-HQ-OAR-2008-0664) when they are available.  

The Agency believes sufficient technical information on the TFA
deposition from HFO-1234yf is available for the basis of this proposal;
however, the Agency welcomes additional comment on HFO-1234yf’s
environmental and atmospheric effects.  The Agency will give the
greatest weight to published, peer-reviewed studies.  The Agency
requests comment on the impact of increased abundance of TFA resulting
from the use of HFO-1234yf as an MVAC refrigerant in the U.S., and the
potential impacts of U.S. and worldwide use of HFO-1234yf as an MVAC
refrigerant.  The National Oceanic and Atmospheric Administration (NOAA)
informed EPA that a follow-on study of the Papadimitriou 2007 work is
underway.  EPA anticipates the results of this study will be published
and be made publicly available before the Agency issues a final rule on
the acceptability of HFO-1234yf under the SNAP Program.  If the study
becomes available, EPA will consider that information in determining how
to move forward on this proposed determination for HFO-1234yf.

Currently available analysis on the atmospheric and local air quality
impacts of HFO-1234yf assumes an emissions rate very similar to
HFC-134a.  This assumption leads to a very conservative emission rate
because it is highly likely HFO-1234yf will have a lower leak rate
compared to HFC-134a because HFO-1234yf will cost approximately ten
times more than HFC-134a.  There will be an economic basis for
conserving and preventing the release of HFO-1234yf.    

B.  General Population Risks from Ambient Exposure to Compounds with
Direct Toxicity and to Increased Ground-Level Ozone

Toxicity:

EPA’s New Chemicals Program (http://www.epa.gov/oppt/newchems/),
mandated by Section 5 of the Toxic Substances Control Act (TSCA),
conducted a premanufacture review of HFO-1234yf.  This review assessed
the potential environmental and human health risks associated with the
substance (insert PMN Docket # when available).  Based on test data on
HFO-1234yf, EPA has human health concerns for developmental toxicity and
lethality via inhalation exposure.  

The Workplace Environmental Exposure Limit (WEEL) Committee of the
American Industrial Hygiene Association has established a WEEL of 500
parts per million (ppm) by volume on an eight-hour time-weighted average
(TWA) for HFO-1234yf.  See the docket for the WEEL Committee rationale. 
The Committee established a WEEL of 1,000 ppm by volume on an eight-hour
TWA for HFC-134a.  

In terms of cardiotoxicity, HFC-134a is a cardiac sensitizer at 75,000
ppm with a no observable adverse effect level (NOAEL) of 50,000 ppm. 
HFO-1234yf is negative in the cardiac sensitization test at exposures of
up to 120,000 ppm. (insert PMN Docket # when available).  

Ground-level Ozone:

HFO-1234yf could impact local air quality (LAQ) through formation of
ground-level ozone.  Photochemical ozone creation potential (POCP)
describes a compound’s potential to form ground-level ozone. 
HFO-1234yf has a higher POCP than the predominant MVAC refrigerant,
HFC-134a.  HFO-1234yf has a POCP comparable to ethylene; ethylene is an
alkene.  According to the Intergovernmental Panel on Climate
Change/Technology and Economic Assessment Panel Special Report, alkenes
“have the potential to significantly influence ozone formation on the
urban and regional scales.”  Papadimitriou et al. (2007) indicate
that, “studies are needed to quantify the degradation of [HFO-1234yf]
under atmospheric conditions for OH- and Cl- atom-initiated chemistry to
fully evaluate the impact of these compounds and their degradation
products on climate and air quality.”  An initial assessment says that
HFO-1234yf could potentially increase ground level ozone by >1-7% in
certain areas, which may affect attainment with the National Ambient Air
Quality Standard for ozone (ICF, 2009).  EPA notes that HFO-1234yf is
defined as a volatile organic compound under Clean Air Act regulations
(see 40 CFR 51.100(s)) addressing the development of State
Implementation Plans (SIPs) to attain and maintain the national ambient
air quality standards.  The Agency requests comment on the LAQ impacts
of HFO-1234yf use as an MVAC refrigerant in the U.S. and globally.  The
Agency would give the greatest weight to peer-reviewed, published papers
for comments on LAQ impacts.  As stated earlier, NOAA’s follow-on
study of HFO-1234yf is expected before the Agency issues a final rule on
the acceptability of HFO-1234yf under the SNAP Program.  In the
meantime, the Agency requests comment on whether a >1-7% increase in
ground level ozone is significant.  

C.  Ecosystem Risks

See discussion under Atmospheric Effects and Related Health and
Environmental Impacts.

D.  Occupational Risks

Occupational risks could come about during the manufacture of the
refrigerant, initial installation of the refrigerant at the car assembly
plant or servicing of the MVAC system.  The TSCA New Chemicals Program
review of HFO-1234yf determined that significant industrial or
commercial worker exposure is unlikely due to CAA section 609 technician
training, the use of CAA section 609 certified refrigerant handling
equipment, and other protective measures.  Therefore, the proposed
manufacture, processing, and use of HFO-1234yf are not expected to
present an unreasonable risk to workers.  More details can be found at
PMN program’s docket for HFO-1234yf.    

In regards to flammability, with proper mitigation and training, the
frequency of exposure to flammable HFO-1234yf concentrations in service
situations can be managed.  Based on feedback from certified MVAC
service technicians, EPA believes that the flammability potential of
HFO-1234yf is within the range of other substances that automotive
service technicians encounter routinely (See docket
EPA-HQ-OAR-2004-0488-0017).  Training, mitigation, and limiting the
frequency of exposure can reduce any potential risks to the technicians.
 Input from technicians confirms this perspective.  Some car
manufacturers have suggested that new training for HFO-1234yf should be
required for all MVAC technicians.  EPA requests comment on whether
additional training for service technicians on HFO-1234yf should be
required so that they are knowledgeable about the different hazards
associated with working on HFO-1234yf MVAC systems compared to the two
systems currently in use – i.e., CFC-12 or HFC-134a systems.  Any
specific training requirements would be adopted in a follow-up Section
609 rulemaking.  At this point, EPA recommends, but does not propose to
require, additional training and requests input on the need for required
training for persons using HFO-1234yf in an MVAC
service/maintenance/disposal scenario.  

E.  Consumer Risks 

Risks to consumers as vehicle occupants have been evaluated, in the
context of HFO-1234yf’s flammability and toxicity.  

Based on American Society of Heating, Refrigerating, and
Air-Conditioning Engineers (ASHRAE) Standard 34 testing, HFO-1234yf’s
lower flammability limit (LFL) is 6.2% and upper flammability limit is
12.3% (Gradient, 2008), making this refrigerant less flammable than
HFC-152a, the only flammable SNAP-approved MVAC refrigerant.  Depending
on the charge size of an HFO-1234yf MVAC system, which can range from as
little as 400 grams to as much as 1600 grams (ICF, 2008a), it is
possible in a worst case scenario to reach a flammable concentration of
HFO-1234yf inside the passenger compartment.  

In terms of toxicological concerns, the TSCA New Chemicals Program
review of HFO-1234yf determined that potential consumer (passenger)
exposure from refrigerant leak into the passenger compartment of a
vehicle is not expected to present an unreasonable risk.  However,
consumer exposure from filling, servicing, or maintaining MVAC systems
without professional training and the use of CAA Section 609 certified
equipment may present an unreasonable risk.  Therefore, to prevent this
risk EPA intends to promulgate a Significant New Use Rule (SNUR) under
section 5(a)(2) of TSCA that would require submission of a Significant
New Use Notice to EPA at least 90 days before any non-professional
servicing, maintenance, and disposal of HFO-1234yf (insert PMN Docket #
when available).

F.  Flammability

The proposed upper limit of occupant exposure to HFO-1234yf protects
against the possibility of flammability.  It is important to note that
when burned or exposed to high heat, HFO-1234yf like all fluorocarbons,
including CFC-12 and HFC-134a, forms acid byproducts including
hydrofluoric acid (HF) - a severe respiratory irritant.   The
Occupational Safety and Health Administration (OSHA) has set a
Permissible Exposure Limit (PEL) 8-hour occupational exposure limits for
HF at 3 ppm which is the upper allowable limit for worker exposure. 
Passenger exposure to HF could occur as a result of a leak in the
presence of an ignition source.  EPA’s approach in setting use
conditions is to prevent any fire risk associated with HFO-1234yf use in
MVAC systems, which would also prevent any potential passenger exposure
to HF.  EPA understands that there is work currently underway that
examines the issue of pre-ignition HF formation.  If those studies
indicate the potential for significant pre-ignition HF formation, EPA
will consider that information in determining how to move forward with
this proposed rule.  Additionally, EPA welcomes any comment on that
study or other studies of which EPA is not aware that address the
potential for pre-ignition HF formation. 

Flammable concentrations inside the passenger compartment

SAE International commissioned a risk assessment of HFO-1234yf in MVAC
systems (Gradient, 2008) based on the analytical framework developed by
EPA and the U.S. Army in a 2006 alternative refrigerant risk analysis
(EPA-HQ-OAR-2004-0488-0025.2).  The risk assessment incorporated the
results of computational fluid dynamic (CFD) modeling (by DuPont) of an
HFO-1234yf leak into the passenger compartment.  DuPont conducted a
limited assessment of refrigerant leakage into the passenger compartment
by modeling the first 200 seconds of a leak into the passenger
compartment.  Based on their analysis, at least one of their simulations
(idle vehicle, low fan, 0.5mm orifice leak, and recirculation mode), led
to exceeding the HFO-1234yf LFL inside the passenger compartment.   To
supplement these results, SAE International updated the modeling results
with field test assessments of leaking refrigerant into the passenger
compartment of Renault/PSA/Fiat and General Motors medium and small size
cars.  The test results show that there are some scenarios where the LFL
was exceeded (Gradient, 2009).  According to the SAE International risk
assessment report, there is “a potential ignition hazard if a
smoking-related ignition source is present” (Gradient, 2008).  
However, the report references a separate field study performed by
Exponent where an experimental release of HFO-1234yf was released into
the passenger and engine compartment of a large vehicle, a 1997 Ford
Crown Victoria (Exponent, 2008).  In this field study, tested releases
of HFO-1234yf did not produce concentrations above the LFL. Given the
fact that flammable conditions can come about in the passenger
compartment, particularly in medium and small size cars, the Agency
believes it is appropriate to adopt a cautionary approach and to propose
a use condition that addresses a possible ignition hazard.

The Agency requests public comment on the SAE International/DuPont and
Exponent reports.  Specifically, the Agency requests comment on the
appropriateness of the simulated charge size that was used by each
report.  The SAE International/DuPont report simulated a 2001 Ford Crown
Victoria with a 691 gram HFO-1234yf charge.  The Exponent report used a
1997 Ford Crown Victoria with a charge size of 693 grams.  The 1997 and
2001 Ford Crown Victorias were originally designed with approximately
966 gram and 1097 grams HFC-134a charge size systems (MACS, 2005). 
Honeywell presentations have indicated the HFO-1234yf charge size is
90-95% of a HFC-134a charge size (Honeywell, 2008).  Based on the
original refrigerant charge size of these Crown Victorias, the
HFO-1234yf charge sizes, in both simulations, are not consistent with
the 90-95% HFC-134a charge sizes described in Honeywell presentations
and the Crown Victorias are undercharged.  Charge size is an important
element in determining the probability of a flammable concentration. 
EPA requests comment on whether the charge sizes used in the DuPont and
Exponent simulations are consistent with the actual charge sizes that
would need to be used in MVAC for these vehicles.  

The Agency also requests comment on the use of a large-size car as for a
worst-case car scenario for a MVAC risk assessment.  Based on an
analysis done in 2004-2005, the EPA/U.S. Army risk assessment (Docket
No. EPA-HQ-OAR-2004-0488-0025.2) concluded large passenger cars provided
the highest ratio of refrigerant charge to interior compartment volume,
and large passenger cars were broadly representative of the world fleet.
 Since that analysis was performed, there is data to indicate the sales
of small cars have increased, and such sales are likely to continue to
increase given a manufacturing shift towards smaller cars (ICF, 2008b). 
A recent analysis showed higher ratios of refrigerant charge to interior
compartment volume in small trucks and two-seaters, compared to the
large car used in SAE’s risk assessment (ICF, 2008a).  A higher ratio
of refrigerant charge to interior compartment volume could lead to more
occurrences of flammable concentrations.  

Flammable concentrations in the engine compartment

According to the SAE International report, “the highest value measured
in the engine compartment (87,000 ppm) suggests a potential ignition
hazard” (Gradient, 2008).  Although an engine compartment field test
suggested that it was not possible to ignite HFO-1234yf (Dupont 2008),
temperatures that could ignite the refrigerant exist on the exhaust
manifold.  Most car manufacturers cover the exhaust manifold with a heat
shield, but this is not a requirement.  EPA requests comment on the
proposed use condition that requires protective devices under the
vehicle hood to avoid any flammable concentrations of refrigerant coming
into the vicinity of hot exhaust manifold surfaces. 

Hybrid and electric vehicle sales in the U.S. have dramatically
increased over the past decade (ICF, 2008b).  To address this change in
the market, EPA considered the potential for another ignition source
from the electric power source in hybrid and electric cars that is not
present with gasoline-only vehicles.  According to DuPont and
Honeywell’s Guidelines for Use and Handling of HFO-1234yf,
“isolation techniques or other suitable methods should be used to
prevent battery and power system sparks/arc.  In areas where processes,
procedures or upset conditions such as leaks have the potential to
generate flammable HFO-1234yf vapor-in-air concentrations in proximity
to hybrid vehicle electric power sources, isolation and/or ventilation
should be used.” (DuPont/Honeywell, 2008).  

In addition, current hybrid vehicles with HFC-134a MVAC systems use
polyolester (POE) oil as a system lubricant, primarily because
polyalkylene glycol (PAG) oils are conductive and can lead to shorts. 
It is not clear if HFO-1234yf MVAC systems can work with the POE oil
that is needed for hybrid vehicles.  The EPA requests comment on whether
the flammability of HFO-1234yf combined with PAG/POE oils may create a
larger concern under the hood of hybrid and electric vehicles.  

EPA is aware of SAE International activities to develop a standard on
specific risk mitigation strategies to avoid flammable concentrations
under the hood.  An excerpt from latest draft of a standard that covers
this topic is available in the docket.  EPA requests comment on using
such an SAE J standard as a use condition to protect against flammable
concentrations under the hood.  If SAE adopts a standard that reflects a
different intent than in the current draft and if EPA determines to
include such a different standard as a use condition, EPA would consider
whether further comment is needed before it issued a final rule with
that use condition. 

Other Flammable Refrigerants and Risk Mitigation

Hydrocarbon refrigerants are unacceptable (prohibited) in MVAC systems
under the SNAP program and are specifically prohibited in several
states.  Hydrocarbons or hydrocarbon blends must not be used in
HFO-1234yf MVAC systems.  

The use conditions described in this action are specific to HFO-1234yf
and do not apply to other flammable refrigerants.  HFO-1234yf is less
flammable and has a higher LFL than HFC-152a, and the proposed use
conditions for HFO-1234yf would not be adequate for HFC-152a.  However,
the interior passenger compartment risk mitigation strategies described
in the HFC-152a proposed and final rules (71 FR 55140 and 73 FR 33304,
respectively) can be protective risk mitigation strategies for
HFO-1234yf.  EPA refers to the previous discussions on HFC-152a risk
mitigation strategies for manufacturers to consider when deciding what
risk mitigation strategies might be used if HFO-1234yf is found
acceptable subject to use conditions.  

	G.  Cost and Availability of the Substitute

Definitive costs for the refrigerant have not been shared with the
Agency.  Based on estimates from Honeywell and DuPont, the cost of
HFO-1234yf will be, at least initially, approximately $40-60/pound
(Weissler, 2008).  The cost of the refrigerant will depend on several
factors, including, but not limited to, how much refrigerant will be
available for sale, the quality of the refrigerant, and where the
refrigerant is manufactured.  The cost of HFO-1234yf will likely be more
than HFC-134a because the HFO-1234yf manufacturing process requires more
energy and more steps than HFC-134a.  

The manufacturers of HFO-1234yf state the chemical can be available when
the market requires it.  At the moment there are no dedicated HFO-1234yf
manufacturing plants.  

H. Proposed Conclusion on Overall Impacts on Human Health and the
Environment

On the whole, EPA proposes that the conditioned use of HFO-1234yf does
not present a significantly larger risk to human health and the
environment compared to HFC-134a, the predominant ODS refrigerant
substitute in passenger vehicle MVAC systems and other SNAP-approved
MVAC refrigerant alternatives, and in many cases likely poses less risk.
 Use conditions are necessary to address the flammability concerns
associated with use of HFO-1234yf.  If it is determined that there are
possible atmospheric effects of HFO-1234yf, those would be controlled by
Clean Air Act Section 608 and Section 609 regulatory requirements that
prohibit the venting, or release, of refrigerant during the service,
maintenance and disposal of refrigeration and A/C equipment.  EPA
welcomes comment on this proposal; the Agency prefers peer-reviewed,
published papers for supporting documentation on comments concerning
technical issues.  

The conditions we are proposing for the safe use of HFO-1234yf are
outlined below.  

V.  HFO-1234yf  MVAC System Proposed Use Conditions

Use Conditions for HFO-1234yf

EPA proposes to find HFO-1234yf acceptable with use conditions in new
MVACs as a substitute for CFC-12.  This proposed determination is
limited to MVAC systems on passenger cars and light-duty trucks; this
proposed determination does not include any other MVAC systems,
including those on buses, trains, boats, off-road equipment, or other
vehicles.  The submission did not specifically request use in these
other MVAC systems and the risks associated with these MVAC systems have
not been evaluated.

EPA proposes to find HFO-1234yf acceptable with the following use
conditions:

HFO-1234yf MVAC systems must incorporate engineering strategies and/or
devices so that leaks into the passenger compartment do not result in
HFO-1234yf concentrations at or above the lower flammability limit (LFL)
of 6.2% v/v for more than 15 seconds;

HFO-1234yf MVAC systems must incorporate engineering strategies and/or
devices so that leaks into the engine compartment or vehicle electric
power source storage areas do not result in HFO-1234yf concentrations at
or above the LFL of 6.2% v/v for any period of time;

HFO-1234yf MVAC systems must incorporate protective devices, isolation
and/or ventilation techniques in areas where processes, procedures or
upset conditions such as leaks have the potential to generate HFO-1234yf
concentrations at or above 6.2% v/v in proximity to hybrid/electric
vehicle electric power sources and exhaust manifold surfaces;

HFO-1234yf MVAC systems must use unique fittings to be identified
pursuant to SAE standard J639 and subject to EPA approval;

HFO-1234yf MVAC systems must include a detailed label identifying the
refrigerant and that the refrigerant is flammable; 

HFO-1234yf MVAC systems must have a high-pressure compressor cutoff
switch installed on systems equipped with pressure relief devices; and

Manufacturers must conduct and keep on file Failure Mode and Effect
Analysis (FMEA) on the MVAC as stated in SAE J1739.  

EPA requests public comment on the proposed use conditions for
HFO-1234yf.  Amongst other topics, EPA requests comment on whether
interior passenger compartment limits to HFO-1234yf should apply only
when the vehicle ignition is ‘on.’  

General SNAP MVAC Use Conditions

On October 16, 1996, EPA promulgated a final rule (61 FR 54029)
establishing certain conditions on the use of any refrigerant used as a
substitute for CFC-12 in MVAC systems (appendix D to subpart G of 40 CFR
part 82).  That rule provides that EPA would list new refrigerant
substitutes in future notices of acceptability and all such refrigerants
would be subject to the use conditions stated in that rule.  Therefore,
EPA is establishing a use condition that unique fittings must be
identified pursuant to SAE standard J639 adopted in 2009 and approved by
EPA.

VI. Additional Information Requested

The Agency seeks comments on topics related to HFO-1234yf that are
beyond the scope of this Section 612 proposed rulemaking regarding use
of HFO-1234yf in new MVAC systems, but which could be relevant to future
actions on HFO-1234yf as a substitute refrigerant.  Please send
information on any of the following issues to Karen Thundiyil,
thundiyil.karen@epa.gov.

Retrofit Use of HFO-1234yf 

The Honeywell submission requested SNAP review of HFO-1234yf in new MVAC
applications only.  Honeywell did not petition the Agency to review
retrofit use of HFO-1234yf.  The Agency has not fully evaluated the
safety issues associated with using HFO-1234yf to service existing
CFC-12 or HFC-134a designed MVAC systems. EPA rules prohibit the use of
flammable refrigerants in retrofit systems. 40 CFR part 82, subpart 2,
App. B (61 FR 54029).  Any person interested in using HFO-1234yf in
retrofit systems would need to petition EPA to change the existing
unacceptable determination.  Such an option would require a separate
SNAP submission and evaluation by EPA.  EPA suspects that car
manufacturers are the best qualified, and likely the only qualified
entity to undertake such an application given the complexities of going
to HFO-1234yf.  The Agency requests comment on whether retrofit kits can
effectively meet the requirements identified in this proposal for new
MVAC systems and if retrofit have a detrimental impact on the MVAC
system fuel efficiency.  The Agency also specifically requests comments
from car manufacturers on retrofitting existing MVAC systems to
HFO-1234yf.  

Retrofitting HFO-1234yf MVAC Systems to Other Alternative Refrigerants

Individuals, service shops, or manufacturers might consider refilling or
charging MVAC systems designed for HFO-1234yf with another refrigerant. 
The Agency has not evaluated the safety issues associated with
retrofitting HFO-1234yf MVAC systems with other MVAC refrigerants
previously approved under SNAP.  Because other refrigerants may be less
expensive, the Agency is concerned that consumers may consider
retrofitting HFO-1234yf systems to use other refrigerants.  The use
conditions proposed for HFO-1234yf are specific to the properties of
this chemical, and would not be protective of fire hazards that may come
about from, for example, hydrocarbon refrigerant (HCR) that is more
flammable.  HCRs are more flammable than HFO-1234yf.  Besides the safety
concerns of retrofitting to another refrigerant, the practice could lead
to increased refrigerant emissions because of materials compatibility
or/and leakage due to hose permeation.

This practice may come about if the price of HFO-1234yf is high, or if
there is limited supply of HFO-1234yf.  EPA requests comments on this
type of retrofitting, and provisions that need to be made to address
this issue, particularly in the context of SNAP’s general requirement
for unique fittings for each unique SNAP listed refrigerant.  

VII. Section 609 Requirements for HFO-1234yf

Service equipment, technician certification and end-of-life disposal
specifications will be addressed in a follow-on rulemaking(s) under
Section 609 of the Clean Air Act.   

VIII.   Statutory and Executive Order Reviews

A.  Executive Order 12866:  Regulatory Planning and Review 

Under Executive Order (EO) 12866   SEQ CHAPTER \h \r 1 (58 FR 51735,
October 4, 1993), this action is a "significant regulatory action.”  
SEQ CHAPTER \h \r 1  It raises novel legal or policy issues arising out
of legal mandates, the President's priorities, or the principles set
forth in the Executive Order.  Accordingly, EPA submitted this action to
the Office of Management and Budget (OMB) for review under EO 12866 and
any changes made in response to OMB recommendations have been documented
in the docket for this action.

B.  Paperwork Reduction Act

This action does not impose any new information collection burden. 
Burden is defined at 5 CFR 1320.3(b).   This proposed rule is an Agency
determination.  It contains no new requirements for reporting.  The only
recordkeeping requirement involves customary business practice.  The
Office of Management and Budget (OMB) has previously approved the
information collection requirements contained in the existing
regulations in subpart G of 40 CFR part 82 under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned OMB
control numbers 2060-0226 (EPA ICR No. 1596.05).  This Information
Collection Request (ICR) included five types of respondent reporting and
record keeping activities pursuant to SNAP regulations:  submission of a
SNAP petition, filing a SNAP/TSCA Addendum, notification for test
marketing activity, record keeping for substitutes acceptable subject to
use restrictions, and record-keeping for small volume uses.  This
proposed rule requires minimal record-keeping of studies done to ensure
that MVAC systems using HFO-1234yf meet the requirements set forth in
this rule.  Because it is customary business practice that automotive
systems manufacturers and automobile manufacturing companies conduct and
keep on file failure mode and effect analysis (FMEA) on any potentially
hazardous part or system, we believe this requirement will not impose an
additional paperwork burden.

C.  Regulatory Flexibility Act (RFA)

The RFA generally requires an agency to prepare a regulatory flexibility
analysis of any rule subject to notice and comment rulemaking
requirements under the Administrative Procedure Act or any other statute
unless the agency certifies that the rule will not have a significant
economic impact on a substantial number of small entities.  Small
entities include small businesses, small organizations, and small
governmental jurisdictions.  

For purposes of assessing the impacts of today's rule on small entities,
small entity is defined as: (1) a small business as defined by the Small
Business Administration’s (SBA) regulations at 13 CFR 121.201; for
NAICS code 336111 (Automobile manufacturing), it is <1000 employees; for
NAICS code 336391 (Motor Vehicle Air-Conditioning Manufacturing), it is
<750 employees;  (2) a small governmental jurisdiction that is a
government of a city, county, town, school district or special district
with a population of less than 50,000; and (3) a small organization that
is any not-for-profit enterprise which is independently owned and
operated and is not dominant in its field.

After considering the economic impacts of this proposed rule on small
entities, we certify that this action will not have a significant
economic impact on a substantial number of small entities.  This
proposed rule will not impose any requirements on small entities. The
requirements of this proposed rule impact car manufacturers and car air
conditioning system manufacturers only; none of these businesses qualify
as small entities.  Additionally, car manufacturers and car air
conditioning system manufacturers are not mandated to move to HFO-1234yf
MVAC systems.  EPA is simply listing HFO-1234yf as an acceptable
alternative with use conditions in new MVAC systems.  This rule allows
the use of this alternative to ozone depleting substances in the MVAC
sector and outlines the conditions necessary for safe use.  By approving
this refrigerant under SNAP, EPA provides additional choice to the
automotive industry which, if adopted, would reduce the impact of MVACs
on the global environment.  This rulemaking does not mandate the use of
HFO-1234yf as a refrigerant in new MVACs. 

We continue to be interested in the potential impacts of the proposed
rule on small entities and welcome comments on issues related to such
impacts.

D.  Unfunded Mandates Reform Act

This rule does not contain a Federal mandate that may result in
expenditures of $100 million or more for State, local, and tribal
governments, in the aggregate, or the private sector in any one year. 
EPA has determined that this rule contains no regulatory requirements
that might significantly or uniquely affect small governments.  This
regulation applies directly to entities that manufacture MVAC systems
with the proposed substitute, and not to governmental entities.  This
proposed rule does not mandate a switch to this substitute, but rather
adds to the list of available substitutes from which a manufacturer may
choose; consequently, there is no direct economic impact on entities
from this rulemaking.  Also, production-quality HFO-1234yf MVAC systems
are not manufactured yet.  Consequently, no change in business practice
is required by this proposed rule.  This action provides additional
technical options allowing greater flexibility for industry in designing
consumer products.  Thus, this rule is not subject to the requirements
of sections 202 or 205 of UMRA.

This rule is also not subject to the requirements of section 203 of UMRA
because it contains no regulatory requirements that might significantly
or uniquely affect small governments.  As noted above, this proposed
regulation would not apply to any governmental entity.  EPA has
determined that this rule does not contain a Federal mandate that may
result in expenditures of $100 million or more for State, local, and
tribal governments, in the aggregate, or the private sector in any one
year.  

E.  Executive Order 13132: Federalism

Executive Order 13132, entitled “Federalism” (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
“meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.”
 “Policies that have federalism implications” is defined in the
Executive Order to include regulations that 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.”  

This proposal 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, as
specified in Executive Order 13132.  This regulation applies directly to
entities that manufacture MVAC systems with the proposed substitute and
not to governmental entities.  Thus, Executive Order 13132 does not
apply to this rule.

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

This action does not have tribal implications, as specified in Executive
Order 13175 (65 FR 67249, November 9, 2000).  This proposed rule does
not significantly or uniquely affect one or more Indian tribes, the
relationship between the Federal Government and Indian tribes, or the
distribution of power and responsibilities between the Federal
Government and Indian tribes because this regulation applies directly to
entities that manufacture MVAC systems with the proposed substitute and
not to governmental entities.  Thus, Executive Order 13175 does not
apply to this action.

	EPA specifically solicits additional comment on this proposed action
from tribal officials.

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

This action is not subject to EO 13045 (62 F.R. 19885, April 23, 1997)
because it is not economically significant as defined in EO 12866, and
because the Agency does not believe the environmental health or safety
risks addressed by this action present a disproportionate risk to
children. This action’s health and risk assessments are contained in
Section IV of this proposed rule.

The public is invited to submit comments or identify peer-reviewed
studies and data that assess effects of early life exposure to
HFO-1234yf.  

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

This action is not a “significant energy action” as defined in
Executive Order 13211 (66 FR 18355 (May 22, 2001)), because it is not
likely to have a significant adverse effect on the supply, distribution,
or use of energy. This action would impact manufacturing alternative
MVAC systems.  Preliminary information indicates that these new systems
will have similar fuel efficiency compared to currently available MVAC
systems.  Therefore, we conclude that this rule is not likely to have
any adverse effects on energy supply, distribution or use.

I.  National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of
1995 (“NTTAA”), Public Law No. 104-113, Section 12(d) (15 U.S.C. 272
note) directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical.  Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies.  NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.  

This proposed rulemaking involves technical standards. EPA proposes to
use the SAE International standard J639, which addresses requirements
for safety and reliability for HFO-1234yf systems.  SAE International is
the international standard setting body for motor vehicle requirements. 
SAE International standards are globally recognized and adopted by all
major car manufacturers and system suppliers.  These standards can be
obtained from http://www.sae.org/technical/standards/.  

EPA welcomes comments on this aspect of the proposed rulemaking and,
specifically, invites the public to identify other potentially
applicable voluntary consensus standards and to  explain why such
standards should be used in this regulation.

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

Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes
federal executive policy on environmental justice.  Its main provision
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 and low-income
populations in the United States.  

EPA has determined that this proposed rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it increases the
level of environmental protection for all affected populations;
HFO-1234yf is a non ozone-depleting substance with a low GWP.  Based on
the toxicological and atmospheric work described earlier, HFO-1234yf
will not have any disproportionately high and adverse human health or
environmental effects on any population, including any minority or
low-income population.  This NPRM proposes to require specific use
conditions for MVAC systems, if car manufacturers chose to make MVAC
systems using this low GWP refrigerant alternative. 

IX.   References 

The documents below are referenced in the preamble.  All documents are
located in the Air Docket at the address listed in section titled
“ADDRESSES” at the beginning of this document.  Unless specified
otherwise, all documents are available in Docket ID No.
EPA-HQ-OAR-2008-0664 at www.regulations.gov.  

REFERENCES:

Dupont and Honeywell.  Guidelines for Use and Handling of HFO-1234yf
(v8.0).

Exponent.  2008.  HFO-1234yf Refrigerant Concentration and Ignition
Tests in Full-Scale Vehicle Passenger Cabin and Engine Compartment.  

Gradient Corporation. 2008.  Risk Assessment for Alternative Refrigerant
HFO-1234yf.  

Gradient Corporation. 2009.  Risk Assessment for Alternative
Refrigerants HFO-1234yf and R-744 (CO2). 

ICF International.  2008a.  Air Conditioning Refrigerant Charge Size to
Passenger Compartment Volume Ratio Analysis.

ICF International.  2008b.  Revised Characterization of U.S. Hybrid and
Small Car Sales (Historical and Predicted) and Hybrid Vehicle Accidents.
 

ICF International.  2009.  Revised Draft Assessment of the Potential
Impacts of HFO-1234yf and the Associated Production of TFA on Aquatic
Communities and Local Air Quality.  

Intergovernmental Panel on Climate Change/ Technology & Economic
Assessment Panel Special Report.  2006.  Safeguarding the Ozone Layer
and the Global Climate System:  Issues Related to Hydrofluorocarbons and
Perfluorocarbons.  Available at http://www.ipcc.ch/ipccreports/sroc.htm

Interior Climate Control Standards Committee of SAE International. 
2009.  Excerpt from draft HFO-1234yf Engine Compartment Safety Standard.

Minor, B., 2008.  CRP-1234: CFD Modeling of a Large Car – Final
Report.  

Mobile Air Conditioning Society Worldwide.  2005.  A/C & Cooling System
Specifications:  1995-2006.  

Papadimitriou, V., R.K. Talukdar, R.W. Portmann, A.R. Ravishankara, and
J.B. Burkholder.  2007.  CF3CF=CH2 and (Z)-CF3CF=CHF:  Temperature
dependent OH rate coefficients and global warming potentials.  Physical
Chemistry Chemical Physics.  9: 1-13.

Scientific Assessment of Ozone Depletion: 2006.  World Meteorological
Organization.  Available at
http://www.wmo.int/pages/prog/arep/gaw/ozone_2006/ozone_asst_report.html

United States Environmental Protection Agency (EPA).  2006.  Risk
Analysis for Alternative Refrigerant in Motor Vehicle Air Conditioning.

Weissler, P., 2008.  Consensus Building on Refrigerant Type.  Automotive
Engineering International.  9: 30-32.

Protection of Stratospheric Ozone:  New Substitute in the Motor Vehicle
Air Conditioning Sector under the Significant New Alternatives Policy
(SNAP) Program (Page   PAGE  37  of   NUMPAGES  39 )

List of Subjects in 40 CFR Part 82	

	Environmental protection, Administrative practice and procedure, Air
pollution control, Reporting and recordkeeping requirements.

DATED: _____________________________________________

____________________________________________________

Lisa P. Jackson,

Administrator.

For the reasons set out in the preamble, 40 CFR Part 82 is proposed to
be amended as follows:

PART 82 - PROTECTION OF STRATOSPHERIC OZONE

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

	

The first table in Subpart G to Appendix B of Part 82 is amended by
adding 1 new entry to the end of the table to read as follows:

Appendix B to Subpart G of Part 82 - Substitutes Subject to Use
Restrictions and Unacceptable Substitutes

REFRIGERANTS-ACCEPTABLE SUBJECT TO USE CONDITIONS

Application	Substitute	Decision	Conditions	Comments

*******

CFC-12 Automobile Motor Vehicle Air Conditioning

 (New equipment in passenger cars and trucks only)	

HFO-1234yf as a substitute for CFC-12	

Acceptable subject to use conditions	

Engineering strategies and/or devices must be incorporated into the
system such that leaks into the free space of the passenger compartment
do not result in HFO-1234yf concentrations of 6.2% v/v or above in any
part of the free space1 inside the passenger compartment for more than
15 seconds.  

Engineering strategies and/or devices must be incorporated into the
system such that leaks into the engine compartment or vehicle electric
power source storage areas do not result in HFO-1234yf concentrations of
6.2% v/v or above for any period of time.

HFO-1234yf MVAC systems must incorporate protective devices, isolation
and/or ventilation techniques in areas where processes, procedures or
upset conditions such as leaks have the potential to generate HFO-1234yf
concentrations at or above 6.2% v/v in proximity to exhaust manifold
surfaces and hybrid/electric vehicle electric power sources.

Manufacturers must adhere to all the safety requirements listed in the
Society of Automotive Engineers (SAE) Standard J639 (adopted 2009),
including unique fittings and flammable refrigerant warning label and
high-pressure compressor cutoff switch and pressure relief devices.

Manufacturers must conduct and keep on file Failure Mode and Effect
Analysis (FMEA) on the MVAC as stated in SAE J1739 (adopted 2009).  

	

Additional training for service technicians recommended.

Observe Pre-manufacture Notice (PMN) regulatory decision. 



 HFO-1234yf is also known as HFC-1234yf, R-1234yf  or
2,3,3,3-tetrafluoropropene, CAS Reg. No. 754-12-1. 

 CFC-12 is also known as dichlorodifluoromethane, R-12, or Freon®-12,
CAS Reg. No. 75-71-8.

 Unless stated otherwise, flammability limits discussed here are by
volume.

 The National Oceanic and Atmospheric Administration is currently
reviewing the ODP of HFO-1234yf and we will place this information in
the docket if it becomes available during the course of this rulemaking.

 These decomposition products have a sharp, acrid odor even at
concentrations of only a few parts per million.  

1 Free space is defined as the space inside the passenger compartment
excluding the space enclosed by the ducting in the HVAC module

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