[Federal Register Volume 91, Number 2 (Monday, January 5, 2026)]
[Notices]
[Pages 275-277]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-24258]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OPPT-2025-3358; FRL-13124-01-OCSPP]


Science Advisory Committee on Chemicals (SACC); Request for 
Nominations of Ad Hoc Peer Reviewers

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: The Environmental Protection Agency (EPA or the Agency) is 
seeking nominations of scientific and technical experts that EPA can 
consider for service as ad hoc peer reviewers assisting the Science 
Advisory Committee on Chemicals (SACC). EPA is considering peer review 
for ten Toxic Substances Control Act (TSCA)-designated High-Priority 
chemicals. EPA will convene two SACC peer review meetings anticipated 
to occur in early and mid-2026. EPA is conducting these chemical review 
evaluations to help inform whether the chemical substances present 
unreasonable risks to human health and/or the environment under the 
conditions of use, as required by TSCA. Any interested person or 
organization may nominate qualified individuals to be considered 
prospective candidates for these reviews by following the instructions 
provided in this document. Individuals may also self-nominate.

DATES: Submit your nominations on or before February 4, 2026.

ADDRESSES: Submit your nomination via email to [email protected] following 
the instructions in Unit III. Do not electronically submit any 
information you consider to be Confidential Business Information (CBI) 
or other information whose public disclosure is restricted by statute. 
If your nomination may contain any such information, please contact the 
Designated Federal Officer (DFO) in FOR FURTHER INFORMATION CONTACT to 
obtain special instructions before submitting that information.

FOR FURTHER INFORMATION CONTACT: The DFO and Executive Secretary for 
the SACC is Tamue Gibson, Regulatory & Information Services Division 
(7602M), Office of Mission Critical Operations, Office of Chemical 
Safety and Pollution Prevention, Environmental Protection Agency; 
telephone number: (202) 564-5336 or call the SACC main office at (202) 
564-8450; email address: [email protected].

SUPPLEMENTARY INFORMATION:

I. General Information

A. 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 and mixtures. 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.

B. What should I consider as I prepare my nominations for EPA?

    1. Submitting CBI. Do not submit CBI or other sensitive information 
to EPA through email. If your nomination contains any information that 
you consider to be CBI or otherwise protected, please contact the DFO 
in FOR FURTHER INFORMATION CONTACT to obtain special instructions 
before submitting that information.
    2. Request for Nominations to Serve as ad hoc Expert Reviewers to 
Assist the SACC. As part of a broader process for developing a pool of 
candidates for SACC peer reviews, EPA is asking the public and 
stakeholders for nominations of scientific and technical experts that 
EPA can consider as prospective candidates to serve as ad hoc reviewers 
assisting the SACC with peer reviews. Any interested person or 
organization may nominate qualified individuals for consideration as 
prospective candidates for this review by following the instructions 
provided in this document. Individuals may also self-nominate.
    Those selected from the pool of prospective candidates will be 
invited to attend the public meeting and to participate in the 
discussion of key issues and assumptions at the meeting. In addition, 
they will be asked to review chemical evaluation documents and to help 
finalize the meeting minutes and final report.
1. Peer Review Topics Anticipated for 2026
    Individuals nominated for the two SACC peer reviews anticipated for 
early and mid-2026 should have expertise in one or more of the 
chemicals and/or areas of expertise identified below.
    Early-2026 Chemicals Undergoing Risk Evaluation that EPA is 
Considering for SACC Review:
     1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta 
[g]-2-benzopyran (HHCB)
     Phthalic anhydride (PAD)
     o-Dichlorobenzene (o-DCB)
     p-Dichlorobenzene (p-DCB)
    Individuals nominated for peer review for the early-2026 chemical 
review should also have expertise in one or more of the following 
areas:
    Aquatic exposure modeling; aquatic exposures from ships/ports; 
cancer mechanism of action (MOA); cancer weight-of-evidence (WoE); 
chemical engineering; chemical transport and fate; computational 
toxicology; consumer exposure; dermal exposure modeling (including 
probabilistic modeling) and estimation for workers; dermal 
sensitization; dose-response modeling; epidemiology; inhalation 
toxicology; metabolism; physiologically based pharmacokinetics (PBPK); 
probabilistic modeling for environmental exposures; read-across; 
respiratory sensitization; risk assessment; sediment dynamics; 
toxicokinetics; transcriptomics; and worker exposure.
    Mid-2026 Chemicals Undergoing Risk Evaluation that EPA is 
Considering for SACC Review:
     1,2-Dichloropropane (1,2-DCP)
     1,1,2-Trichloroethane (1,1,2-TCA)
     trans-1,2-Dichloroethylene (trans-DCE)
     Ethylene dibromide (EDB)
     4,4'-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA)
     Phosphoric acid, triphenyl ester (TPP)
    Individuals nominated for peer review for the mid-2026 chemical 
review should have expertise in one or more of the following areas:
    Aquatic exposure modeling; aquatic toxicology; amphibian 
toxicology; avian toxicology; cancer mechanism of action (MOA); cancer 
weight-of-evidence (WoE); chemical engineering (processing as a 
reactant and processing as a plastic processes); chemical transport and 
fate; computational toxicology; consumer exposure; dermal exposure 
modeling (including probabilistic modeling) and estimation for workers; 
dermal sensitization; dose-response modeling; epidemiology;

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exposure modeling-releases from industrial and commercial facilities; 
exposures to firefighters; industrial hygiene; inhalation exposure 
modeling and estimation for workers; inhalation toxicology; metabolism; 
physiologically based pharmacokinetics (PBPK); respiratory 
sensitization; risk assessment; sediment dynamics; toxicokinetics; and 
worker exposure.
2. Nominations
    Nominees should be scientific experts who have sufficient 
professional qualifications, including training and experience, to be 
capable of providing expert comments on the scientific issues for these 
reviews. Each nomination should include the following information:
     Contact information for the person making the nomination;
     Name, affiliation, and contact information for the 
nominee; and
     The disciplinary and specific areas of expertise of the 
nominee.
    Submit your nomination as directed under ADDRESSES by the deadline 
indicated under DATES.
    Those who are selected from the pool of prospective candidates will 
be invited to attend a public SACC meeting and participate in the 
discussion of key issues and assumptions. In addition, they will be 
asked to review and to help finalize the meeting minutes and final 
report.
    SACC members and ad hoc reviewers are subject to the provisions of 
the Standards of Ethical Conduct for Employees of the Executive Branch 
at 5 CFR part 2635, conflict of interest statutes in Title 18 of the 
United States Code and related regulations. In anticipation of this 
requirement, prospective candidates for service on the SACC will be 
asked to submit confidential financial information which shall fully 
disclose, among other financial interests, the candidate's employment, 
stocks, and bonds, and where applicable, sources of research support. 
EPA will evaluate the candidates' financial disclosure forms to assess 
whether there are financial conflicts of interest, appearance of a loss 
of impartiality, or any prior involvement with the development of the 
documents under consideration (including previous scientific peer 
review) before the candidate is considered further for service on the 
SACC. Selected candidates are required to complete an ethics training 
prior to conducting their reviews.
3. Selection of Ad Hoc Reviewers
    The selection of scientists to serve as ad hoc reviewers for the 
SACC is based on the function of the Committee and the expertise needed 
to address the Agency's charge to the Committee. No interested 
scientists shall be ineligible to serve by reason of their membership 
on any other advisory committee to a federal department or agency or 
their employment by a federal department or agency, except EPA. Other 
factors considered during the selection process include availability of 
the prospective candidate to fully participate in the Committee's 
reviews, ability to be hired as an EPA Special Government Employee 
(SGE), absence of any conflicts of interest or appearance of loss of 
impartiality, independence with respect to the matters under review, 
and lack of bias. Although financial conflicts of interest, the 
appearance of loss of impartiality, lack of independence, and bias may 
result in non-selection, the absence of such concerns does not assure 
that a candidate will be selected to serve on the SACC. Numerous 
qualified candidates are often identified for SACC reviews. Therefore, 
selection decisions involve carefully weighing several factors 
including the candidates' areas of expertise and professional 
qualifications and achieving an overall balance of different scientific 
perspectives across reviewers.
    At this time, EPA is seeking nominations to create a pool of ad hoc 
experts who can be available to the SACC to assist in reviews conducted 
by the Committee. EPA anticipates selecting experts from this pool, as 
needed, to assist the SACC in their review of the chemicals listed in 
Units II B1. and II.B2. The Agency will consider all nominations of 
prospective candidates for service as ad hoc reviewers for the SACC 
that are received on or before February 4, 2026. However, final 
selection of ad hoc reviewers is a discretionary function of the 
Agency.
    EPA plans to make a list of candidates under consideration as 
prospective ad hoc reviewers for these reviews available for public 
comment. The list will be available in the docket at https://www.regulations.gov (docket identification number EPA-HQ-OPPT-2025-
3358) and through the SACC website at https://www.epa.gov/tsca-peer-review.

II. Background

A. What is the purpose of the SACC?

    The SACC provides independent advice and recommendations to the 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 comprised of experts in 
toxicology; environmental risk assessment; exposure assessment; and 
related sciences (e.g., synthetic biology, pharmacology, biotechnology, 
nanotechnology, biochemistry, biostatistics, physiologically based 
pharmacokinetic (PBPK) modeling, computational toxicology, 
epidemiology, environmental fate, environmental engineering and 
sustainability). The SACC currently consists of 19 members. When 
needed, the committee will be assisted by ad hoc reviewers with 
specific expertise in the topics under consideration.

B. Background on Each Chemical

1. Early 2026 Chemicals Under Consideration
     1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta 
[g]-2-benzopyran (HHCB): HHCB is a synthetic polycyclic musk used in 
fragrances found in cleaners, detergents, and personal care products. 
EPA designated it as a High-Priority Substance for risk evaluation 
under TSCA in 2019. HHCB is released primarily via wastewater pathways 
and may persist in aquatic and sediment environments. EPA's risk 
evaluation will address ecological toxicity, environmental fate, 
bioaccumulation, general population exposures, and human health impacts 
across conditions of use.
     Phthalic Anhydride (PAD): PAD is an industrial 
intermediate used to manufacture alkyd resins, plasticizers, polyester 
resins, pigments, and coatings. EPA designated it as a High-Priority 
Substance for risk evaluation under TSCA in 2019. The draft risk 
evaluation will examine industrial releases, occupational inhalation 
and dermal exposures (including sensitization), consumer exposures, 
environmental fate, and human health hazards.
     o-Dichlorobenzene (o-DCB): o-DCB is used as a solvent, 
degreasing agent, and chemical intermediate. EPA designated it as a 
High-Priority Substance for risk evaluation under TSCA in 2019. Its 
evaluation will focus on inhalation exposures to workers and consumers, 
multimedia environmental transport, and potential health risks 
associated with acute and chronic exposures.
     p-Dichlorobenzene (p-DCB): p-DCB is used in deodorant 
blocks, air fresheners, repellents, and other industrial applications. 
EPA designated it as a High-Priority Substance for risk evaluation 
under TSCA in 2019. It presents inhalation exposure concerns due to its 
volatility and widespread consumer uses. EPA's risk evaluation will 
address health hazards, exposure

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pathways, environmental fate, and risks associated with indoor and 
ambient exposures.
2. Mid-2026 Chemicals Under Consideration
     1,2-Dichloropropane (1,2-DCP): 1,2-DCP is a chlorinated 
solvent used in consumer and industrial cleaning, chemical synthesis, 
and as an intermediate. EPA designated it as a High-Priority substance 
due to concerns for inhalation and dermal exposure and potential 
carcinogenicity. EPA's draft risk evaluation will assess general 
population, occupational and consumer exposures, environmental 
releases, fate and transport, and human health and environmental 
hazards.
     1,1,2-Trichloroethane (1,1,2-TCA): 1,1,2-TCA is used as a 
solvent and chemical intermediate. EPA designated it as a High-Priority 
Substance for risk evaluation under TSCA in 2019. Its evaluation will 
address general population, occupational and consumer exposures via 
inhalation and dermal exposure pathways; environmental releases from 
industrial use; and potential human and environmental health hazards 
including systemic toxicity and carcinogenicity.
     trans-1,2-Dichloroethylene (trans-DCE): trans-DCE is a 
highly flammable, colorless liquid. It is a synthetic chemical with no 
known natural sources, and it is used as a solvent in processing and in 
formulaitons for cleaning and degreasing, among other uses. EPA 
designated it as a High-Prioroty Substance for risk evaluation under 
TSCA in 2019. EPA's risk evaluation will address potentially exposed or 
susceptible subpopulations (PESS), environmental and human health 
hazards, and exposures and impacts across conditions of use.
     Ethylene Dibromide (EDB): EDB is primarily used in 
chemical synthesis and as a fuel additive. It was historically used as 
a fumigant. EDB has known toxicity and potential carcinogenic effects. 
EPA designated it as a High-Priority Substance under TSCA. EPA's draft 
evaluation will consider inhalation and dermal exposures during 
manufacturing, processing and use, environmental fate, ecological 
effects, and health hazards associated with occupational, consumer, and 
general population exposures.
     Tetrabromobisphenol A (TBBPA): TBBPA is a brominated flame 
retardant used in printed circuit boards, resins, and polymer systems. 
EPA designated it as a High-Priority Substance due to potential 
ecological hazards, persistence, and possible endocrine-related 
effects. The risk evaluation will address aquatic and sediment exposure 
pathways, environmental fate, bioaccumulation, and human health risks 
associated with occupational and consumer uses.
     Triphenyl Phosphate (TPP): TPP is used as a flame 
retardant and plasticizer in polymers, electronics, and consumer 
products. EPA designated it as a High-Priority Substance under TSCA. 
TPP may be released to air, water, or dust during use and disposal. 
EPA's risk evaluation will consider exposure to workers and consumers, 
environmental fate, ecological effects, and potential risks across 
conditions of use.

(Authority:15 U.S.C. 2625(o); 5 U.S.C. 10.)

    Dated: December 30, 2025.
Nancy B. Beck,
Principal Deputy Assistant Administrator, Office of Chemical Safety and 
Pollution Prevention.
[FR Doc. 2025-24258 Filed 1-2-26; 8:45 am]
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