
[Federal Register Volume 88, Number 240 (Friday, December 15, 2023)]
[Notices]
[Pages 86894-86896]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-27600]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPPT-2023-0265; FRL-11109-02-OCSPP]


Tris(2-chloroethyl) Phosphate (TCEP); Draft Risk Evaluation Under 
the Toxic Substances Control Act (TSCA); Letter Peer Review; Notice of 
Availability, Public Meeting and Request for Comment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: The Environmental Protection Agency (EPA) is announcing the 
availability of and soliciting public comment on the document titled: 
``2023 Draft Risk Evaluation for Tris(2-chloroethyl) Phosphate (TCEP)'' 
and related draft charge questions. EPA will be submitting the Draft 
Risk Evaluation and public comments to peer reviewers who will consider 
the approach and methodologies utilized. The letter peer review will 
include review of the analysis of physical-chemical properties, the 
fate of TCEP in the environment, releases of TCEP to the environment, 
environmental hazard and risk characterization for terrestrial and 
aquatic species, and human health hazard and risk characterization for 
workers, consumers, and the general population. The letter peer review 
is expected to begin on March 13, 2024, and end on April 12, 2024. A 
preparatory virtual public meeting will be held on March 5, 2024, for 
reviewers and the public to comment on and ask questions regarding the 
scope and clarity of the draft charge questions. Feedback from the 
letter peer review will be considered in the development of the final 
TCEP risk evaluation.

DATES: 
    Virtual Public Meeting: March 5, 2024, 1-4 p.m. EST. To receive the 
webcast meeting link and audio teleconference information before the 
meeting, you must register by 5 p.m. EST on March 1, 2024.
    Special Accommodations: To allow EPA time to process your request 
for special accommodations, please submit the request by February 23, 
2024.
    Written Comments: Comments must be received on or before February 
13, 2024.

ADDRESSES: Submit written comments identified by docket identification 
(ID) number EPA-HQ-OPPT-2023-0265, through https://www.regulations.gov. 
Follow the online instructions for submitting comments. Do not submit 
electronically any information you consider to be Confidential Business 
Information (CBI) or other information whose disclosure is restricted 
by statute. Additional information on commenting or visiting the 
docket, along with more information about dockets generally, is 
available at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: The Peer Review Leader (PRL), Alaa 
Kamel, Ph.D., Mission Support Division, Office of Program Support, 
Office of Chemical Safety and Pollution Prevention, Environmental 
Protection Agency;

[[Page 86895]]

telephone number: (202) 564-5336 or call the main office number: (202) 
564-8450; email address: [email protected].

SUPPLEMENTARY INFORMATION:

I. Executive Summary

A. What action is the Agency taking?

    EPA is announcing the availability of and soliciting public comment 
on the document titled: ``2023 Draft Risk Evaluation for Tris(2-
chloroethyl) Phosphate (TCEP)''. A letter peer review is expected to 
begin on March 13, 2024, and end on April 12, 2024, to review the 
approach and methodologies utilized in this document. A preparatory 
virtual public meeting will be held on March 5, 2024, for reviewers and 
the public to comment on and ask questions regarding the scope and 
clarity of the draft charge questions.

B. What is the Agency's authority for taking this action?

    Section 6(b) of the Toxic Substances Control Act (TSCA) (15 U.S.C. 
2605(b)), requires that EPA conduct risk evaluations on existing 
chemical substances and identifies the minimum components EPA must 
include in all chemical substance risk evaluations. The risk evaluation 
must not consider costs or other non-risk factors (15 U.S.C. 
2605(b)(4)(F)(iii)). The specific risk evaluation process is set out in 
40 CFR part 702 and summarized on EPA's website at https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-evaluations-existing-chemicals-under-tsca.

C. Does this action apply to me?

    This action is directed to the public in general. This action may, 
however, be of interest to those involved in the manufacture, 
processing, distribution, and disposal of chemical substances and 
mixtures, and/or those interested in the assessment of risks involving 
chemical substances regulated under TSCA. Since other entities may also 
be interested, the Agency has not attempted to describe all the 
specific entities that may be affected by this action.

D. What should I consider as I submit my comments to EPA?

    1. Submitting Confidential Business Information (CBI).
    Do not submit CBI or other sensitive information to EPA through 
https://www.regulations.gov or email. If you'd like to include 
information in your comment that you consider to be CBI or otherwise 
protected, please contact the PRL listed under FOR FURTHER INFORMATION 
CONTACT to obtain special instructions before submitting that 
information.
    2. Tips for preparing comments. When preparing and submitting your 
comments, see Tips for Effective Comments at https://www.epa.gov/dockets.

II. Request for Comment

    EPA is seeking public comment on both the draft risk evaluation and 
the draft charge questions for the letter peer review. Both documents 
are available in EPA Docket ID No. EPA-HQ-OPPT-2023-0265 at https://www.regulations.gov and may also be accessed through EPA's website at 
https://www.epa.gov/tsca-peer-review. As additional background 
materials become available, EPA will include those additional 
background documents (e.g., reviewers participating in this letter peer 
review) in the docket and on the website.

III. Preparatory Meeting

    EPA will publish instructions on how to register for the virtual 
public meeting that will be held on March 5, 2024, from 1-4 p.m. EST. 
After registering, you will receive the webcast meeting link and audio 
teleconference information for this public meeting. You may register 
and participate as a listen-only attendee at any time up to the end of 
the meeting on March 5, 2024. Requests to make brief (up to five 
minutes) oral comments during the preparatory meeting can be submitted 
when registering and will be accepted until Friday, March 1, 2024.

IV. Letter Peer Review

A. What is the purpose of this Letter Peer Review?

    The focus of this Letter Peer Review is on the approach and 
methodologies utilized in the ``2023 Draft Risk Evaluation for Tris(2-
chloroethyl) Phosphate (TCEP).'' Feedback from this review will be 
considered in the development of the final TCEP risk evaluation.

B. Why did EPA develop these documents?

    TCEP is a High-Priority substance undergoing the TSCA risk 
evaluation process. TCEP has been primarily used in paint and coating 
manufacturing, and in polymers used in aerospace equipment and 
products. In the past it has also been used in commercial and consumer 
products, including fabric and textile products, foam seating, and 
construction materials. TCEP may also be imported in articles intended 
for consumer use.
    In August 2020, EPA published a final scope document for 20 High-
Priority substances, including TCEP, outlining the hazards, exposures, 
conditions of use, and the potentially exposed or susceptible 
subpopulations the Agency expects to consider in its risk evaluation.
    EPA is submitting the ``2023 Draft Risk Evaluation for Tris(2-
chloroethyl) Phosphate (TCEP)'' and associated supporting documents for 
Letter Peer Review. The Letter Peer Review will include review of the 
analysis of physical chemical properties, the fate of TCEP in the 
environment, releases of TCEP to the environment, environmental hazard 
and risk characterization for terrestrial and aquatic species, and 
human health hazard and risk characterization for workers, consumers, 
and the general population. Specifically, EPA is seeking comment on the 
following issues:
     The list of considerations EPA used to arrive at the human 
health hazard confidence levels and the specific confidence levels 
chosen for individual human health hazard outcomes (neurotoxicity, 
reproductive/developmental effects, kidney effects, and cancer) in the 
TCEP risk evaluation.
     Whether the approach used to estimate anaerobic 
degradation in the absence of data is appropriate for assessing 
anaerobic degradation in sediment.
     Use of the model, Web-based Interspecies Correlation 
Estimation (Web-ICE), to predict acute toxicity hazard values for 
aquatic species not represented in the available studies.
    This is the first time EPA has used Web-ICE in a TSCA risk 
evaluation. These predictions were used with available empirical data 
to create a Species Sensitivity Distribution (SSD). The SSD was used to 
calculate a hazardous concentration for 5% of species 
(HC05). EPA is also using a data-driven way of accounting 
for uncertainty for environmental hazard and is soliciting comment on 
its characterization of this uncertainty, specifically its use of the 
lower bound of the 95% confidence interval of the hazardous 
HC05.
     Human health hazard benchmark dose modeling of animal 
toxicity data for TCEP.
     The list of considerations EPA used to arrive at the human 
health hazard confidence levels and the specific confidence levels 
chosen for individual human health hazard outcomes (neurotoxicity, 
reproductive/developmental effects, kidney effects, and cancer) to 
quantitatively evaluate risk from TCEP.
     Use of several approaches for estimating exposures to 
humans and

[[Page 86896]]

environmental receptors: (1) The use of Verner 2008 Multi-compartment 
model, which was used to assess TCEP exposure to infants through human 
milk for the first time in a TSCA risk evaluation; (2) the use of 
Verner 2008 Multi-compartment model and associated uncertainties in 
extrapolating from the inhalation to oral routes of exposure; (3) the 
use of the American Meteorological Society/Environmental Protection 
Agency Regulatory Model (AERMOD) to estimate air deposition of TCEP. 
EPA has used AERMOD in previous TSCA risk evaluations; however, its use 
in estimating air deposition is novel for TSCA risk evaluations.
     Approach for modeling drinking water contamination from 
wells near municipal solid waste landfills, which is a new approach for 
TSCA risk evaluations.

C. How can I access the documents submitted for review?

    The ``2023 Draft Risk Evaluation for Tris(2-chloroethyl) Phosphate 
(TCEP)'' and all background documents, related supporting materials, 
and draft charge questions are available at https://www.regulations.gov 
in Docket ID No. EPA-HQ-OPPT-2023-0265 and through the TSCA Scientific 
Peer Review Committees website at https://www.epa.gov/tsca-peer-review. 
In addition, as additional background materials become available (e.g., 
reviewers participating in the letter peer review), EPA will include 
those additional background documents in the docket and through the 
website.
    Authority: 15 U.S.C. 2601 et seq.

    Dated: December 12, 2023.
Michal Freedhoff,
Assistant Administrator, Office of Chemical Safety and Pollution 
Prevention.
[FR Doc. 2023-27600 Filed 12-14-23; 8:45 am]
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