[Federal Register Volume 90, Number 180 (Friday, September 19, 2025)]
[Notices]
[Pages 45204-45206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18170]
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ENVIRONMENTAL PROTECTION AGENCY
[EPA-HQ-OPPT-2025-1610; FRL-12975-01-OCSPP]
Octamethylcyclotetrasiloxane (D4); Draft Risk Evaluation; Science
Advisory Committee on Chemicals (SACC) Peer Review; Notice of SACC
Meeting; Availability of Draft Documents and Request for Comment
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: The Environmental Protection Agency (EPA or Agency) is
announcing that there will be two virtual public meetings of the
Science Advisory Committee on Chemicals (SACC). On November 18, 2025, a
preparatory meeting for the SACC to consider the scope and clarity of
the draft charge questions for the peer review; and on December 2
through 5, 2025, a peer review meeting for the SACC to consider the
octamethylcyclotetrasiloxane (D4) draft risk evaluation, technical
support documents, and public comments. EPA is also announcing the
availability of and soliciting public comment on the draft documents
and charge questions that will be provided to the SACC for this peer
review. The draft risk evaluation and technical support documents were
prepared under the Toxic Substances Control Act (TSCA) and will be
submitted to the SACC for peer review.
DATES:
Preparatory Public Meeting
Meeting date: November 18, 2025, 1:00 p.m. to approximately 4:00
p.m. (EST).
Registration: To request time to present oral comments during the
preparatory meeting, you must register by noon (12:00 p.m. EST) on
November 11, 2025, and submit a written version of your oral comments
by noon (12:00 p.m. EST) on November 14, 2025. For those not making
oral comments, registration will remain open through the end of this
meeting on November 18, 2025.
SACC Peer Review Public Meeting
Meeting dates: December 2 through 5, 2025, 10:00 a.m. to
approximately 5:00 p.m. (EST).
Registration: To request time to present oral comments during the
SACC peer review meeting, you must register by noon (12:00 p.m. EST)
November 25, 2025, and submit a written version of your oral comments
by noon (12:00 p.m. EST) on November 28, 2025. For those not making
oral comments, registration will remain open through the end of this
meeting on December 5, 2025.
Comments: Submit written comments on the draft risk evaluation,
technical support documents, and charge questions that will be provided
to the SACC for this peer review on or before November 4, 2025.
Special Accommodations: To allow sufficient time for EPA to process
your request for special accommodations before both the preparatory and
SACC peer review meetings, please submit the request at least ten
business days in advance of the relevant meeting.
ADDRESSES:
Comments: Submit written comments, identified by docket
identification (ID): EPA-HQ-OPPT-2025-1610, through https://www.regulations.gov. Follow the online instructions for submitting
comments. Do not electronically submit any information you consider to
be Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Members of the public should also
be aware that personal information included in any written comments may
be posted on the internet at https://www.regulations.gov. Additional
information on commenting or visiting the docket, along with more
information about dockets generally, is available at https://www.epa.gov/dockets.
Meeting(s) registration: Online registration for the preparatory
meeting
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will be available in October 2025. Online registration for the SACC
peer review meeting will be available in November 2025. Please refer to
the SACC website at https://www.epa.gov/tsca-peer-review. After
registering, you will receive the webcast and streaming service meeting
links and audio teleconference information.
Special accommodation requests: To request an accommodation for a
disability, please contact the Designated Federal Official (DFO) listed
under FOR FURTHER INFORMATION CONTACT.
FOR FURTHER INFORMATION CONTACT: Designated Federal Official (DFO):
Dr. Alaa Kamel, Mission Support Division (7602M), Office of Program
Support, Office of Chemical Safety and Pollution Prevention,
Environmental Protection Agency; telephone number: (202) 564-5336 or
call the SACC main office: (202) 564-8450; email address:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Executive Summary
A. What action is the Agency taking?
EPA is announcing that there will be two virtual public meetings of
the SACC. On November 18, 2025, a preparatory meeting for the SACC to
consider the scope and clarity of the draft charge questions for the
peer review; and on December 2 through 5, 2025, a peer review meeting
for the SACC to consider the D4 draft risk evaluation, technical
support documents, and public comments. EPA is also announcing the
availability of and soliciting public comment on the draft documents
and charge questions that will be provided to the SACC for this peer
review.
B. What is the Agency's authority for taking this action?
EPA established the SACC in 2016 in accordance with TSCA, 15 U.S.C.
2625(o), to provide independent advice and expert consultation with
respect to the scientific and technical aspects of issues relating to
the implementation of TSCA. The SACC operates in accordance with the
Federal Advisory Committee Act (FACA), 5 U.S.C. 10, and supports
activities under TSCA, 15 U.S.C. 2601 et seq., the Pollution Prevention
Act, 42 U.S.C. 13101 et seq., and other applicable statutes.
C. Does this action apply to me?
This action is directed to the public in general and may be of
particular interest to those involved in the manufacture, processing,
distribution, and disposal of the subject chemical substances, and/or
those interested (including members of at-risk communities, non-
governmental organizations, and federal, state, and local officials) in
the assessment of risks involving chemical substances and mixtures
regulated under TSCA.
D. What should I consider as I submit my comments to EPA?
1. Submitting CBI. Do not submit CBI or other sensitive information
to EPA through https://www.regulations.gov or email. To include
information in your comment that you consider to be CBI or otherwise
protected, please contact the DFO 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 the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets. See also the instructions in Unit III.C.
E. How can I stay informed about SACC activities?
You may subscribe to the following listserv for alerts regarding
this and other SACC-related activities: https://public.govdelivery.com/accounts/USAEPAOPPT/subscriber/new?topic_id=USAEPAOPPT_101.
II. Background
A. What is the purpose of the SACC?
The SACC provides independent advice and recommendations to EPA on
the scientific and technical aspects of risk assessments,
methodologies, and pollution prevention measures and approaches for
chemicals regulated under TSCA. The SACC is composed of experts in
toxicology, environmental risk assessment, exposure assessment, and
related sciences (e.g., chemistry, biology, toxicology, pharmacology,
biotechnology, nanotechnology, biochemistry, biostatistics,
physiologically based pharmacokinetic (PBPK) modeling, computational
toxicology, epidemiology, environmental fate, and environmental
engineering and sustainability). When needed, the SACC committee will
be assisted by ad hoc reviewers with specific expertise in the topics
under consideration.
B. Why is EPA conducting these risk evaluations?
TSCA requires EPA to conduct risk evaluations on high-priority
chemical substances and identifies the minimum components EPA must
include in all chemical substance risk evaluations.
The purpose of conducting risk evaluations is to determine whether
a chemical substance presents an unreasonable risk to human health or
the environment under the conditions of use (COUs). These evaluations
include assessing risks to relevant potentially exposed or susceptible
subpopulations. As part of this process, EPA: (1) Integrates hazard and
exposure assessments using the best available science that is
reasonably available to assure decisions are based on the weight of the
scientific evidence, and (2) Conducts peer review for risk evaluation
approaches that have not been previously peer reviewed. For more
information about the three stages of EPA's process for ensuring the
safety of existing chemicals (i.e., prioritization, risk evaluation,
and risk management), go to https://www.epa.gov/assessing- and-
managing-chemicals-under-tsca/how-epa-evaluates-safety-existing-
chemicals.
C. Why did EPA develop these documents?
D4 (CASRN 556-67-2) is a colorless, volatile oily liquid with an
annual total production volume in the United States in 2020 between 250
and 500 million pounds (lb.). The primary uses for D4 are to make other
silicone chemicals with commercial uses including but not limited to
adhesives and sealants, automotive care products, paints and coatings,
and other plastic and rubber products. On March 19, 2020, EPA received
a manufacturer request for a risk evaluation of D4 from Dow Silicones
Corporation, Elkem Silicones USA Corporation, Evonik Corporation,
Momentive Performance Materials, Shin-Etsu Silicones of America, Inc.,
and Wacker Chemical Corporation through the American Chemistry
Council's (ACC's) Silicones Environmental, Health, and Safety Center
(SEHSC). In October 2020, EPA notified ACC SEHSC that the Agency had
granted their manufacturer requested risk evaluation.
EPA is submitting the draft risk evaluation of D4 and associated
technical support documents for external peer review. The draft risk
evaluation includes analyses of physical and chemical properties,
environmental hazard and risk, the fate and transport in the
environment, releases to the environment, exposure to workers, and the
general population, including potentially exposed susceptible
subpopulations, and human health hazard and risk characterization for
workers and the general population.
EPA is not developing charge questions for all aspects of the risk
evaluation but is instead focusing its charge to the SACC on specific
scientific
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areas that need peer review. Many of the methods and analyses used in
this risk evaluation are not novel and have been reviewed in the
development of the tools and approaches used in various agency work
products or in previous TSCA assessments.
D. What is the topic of the planned SACC peer review?
On September 10, 2025, EPA requested nominations of scientific and
technical experts to be considered as ad hoc reviewers assisting the
SACC with the peer review of the draft risk evaluation of D4 under TSCA
(https://www.epa.gov/chemicals-under-tsca/epa-requests-nominations-peer-reviewers-tsca-risk-evaluation-d4). These nominations will help
the agency in selecting approximately seven to eight ad hoc reviewers
to assist the SACC with their review. The SACC and ad hoc reviewers
will provide feedback on novel approaches, unique exposure analyses and
other calculations, and selection of key hazard endpoints for D4 as
follows:
Identification of hazards relevant to human health risk
assessment.
Evaluation and use of the D4 physiologically based
pharmacokinetic (PBPK) model.
Handling of uncertainties associated with exposure and
release assessments.
Characterization of bioaccumulation, bioconcentration,
biomagnification, and potential trophic transfer.
Human fish consumption for the general population and
potentially exposed or susceptible subpopulations.
Identification of hazards relevant to ecological risk
assessment.
III. Virtual Public Meetings of the SACC
A. What is the purpose of the virtual public meeting(s)?
The purpose of the preparatory meeting is for the SACC to consider
and ask questions regarding the scope and clarity of the draft charge
questions. The purpose of the peer review meeting is for the SACC to
consider, and peer review the draft risk evaluation and technical
support documents. These public meetings are part of the SACC's peer
review of the Agency's methods and novel analyses for the D4 draft risk
evaluation. The agenda for these meetings will be posted in the docket
and will also be available through the SACC website.
EPA will consider recommendations from this SACC review and public
comments in the development of the TSCA risk evaluations and may inform
other EPA efforts related to the assessment and regulation of the
chemical substances. The Agency will be seeking SACC review of its data
analyses and methodologies relevant to human health hazard and exposure
analyses that have not been previously peer reviewed.
B. How can I participate in the virtual public meetings?
To participate in these virtual public meetings, you must register
online to receive the webcast and streaming service meeting links and
audio teleconference information for each meeting. Online registration
will be available approximately one month prior to the meetings and
will remain open through the end of the meetings. To make oral comments
during one of these meetings, follow the instructions in this document.
C. How can I access the documents?
The draft risk evaluation, technical support documents, and draft
charge questions are available in docket ID: EPA-HQ-OPPT-2025-1610. EPA
will include additional meeting background materials as they become
available, (e.g., SACC members and the meeting agenda) in the docket
and through the Peer Review of the Draft Risk Evaluation for
Octamethylcyclotetrasiloxane (D4) website at https://www.epa.gov/tsca-peer-review/peer-review-draft-risk-evaluation-octamethylcyclotetrasiloxane-d4.
D. How can I provide comments?
To ensure proper receipt of comments, it is imperative that you
identify docket ID: EPA-HQ-OPPT-2025-1610 in the subject line on the
first page of your comments and follow the instructions in this
document.
1. Written comments. Submit written comments by the deadlines set
in the DATES section of this document and as described in the ADDRESSES
section of this document.
2. Oral comments. To request time to present oral comments during
one of the virtual public meetings, you must register online by the
deadlines set in the DATES section of this document. Oral comments
during the peer review meeting are limited to five minutes unless
arrangements have been made with the DFO, within the constraints of the
meeting agenda, prior to November 21, 2025. In addition, each speaker
should submit a written copy of their oral comments and any supporting
materials (e.g., presentation slides) to the DFO prior to the meetings
for distribution to the SACC by the deadlines set in the DATES section
of this document.
IV. Next Steps
After the peer review meeting, the SACC will prepare the meeting
minutes and final report document summarizing its recommendations to
EPA, which will also be available in the docket and through the SACC
website. EPA will consider the SACC recommendations and public comments
to complete the risk evaluation and unreasonable risk determinations
under TSCA for this chemical substance. Under TSCA, EPA must then
initiate risk management actions to address the unreasonable risk it
identified.
Authority: 15 U.S.C. 2625(o); 5 U.S.C. 10.
Dated: September 16, 2025.
Nancy B. Beck,
Principal Deputy Assistant Administrator, Office of Chemical Safety and
Pollution Prevention.
[FR Doc. 2025-18170 Filed 9-18-25; 8:45 am]
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