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 July 23, 2026, there will be a preparatory meeting for the SACC to consider the scope and clarity of the draft charge questions for the peer review; and on August 3 through 7, 2026, there will be a peer review meeting for the SACC to consider draft technical support documents for 1,2-DCP, 1,1,2-TCA, tDCE, TBBPA, and EDB, and their public comments. EPA is also announcing the availability of and soliciting public comments on the draft documents and charge questions that will be provided to the SACC for this peer review in docket ID number EPA-HQ-OPPT-2026-2246 at https://www.regulations.gov. in the docket and available here: https://www.epa.gov/​tsca-peer-review.

This document provides instructions for accessing the materials, submitting written comments, and registering to provide oral comments and attending the public meetings.

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 ( printed page 37107) the scientific and technical aspects of issues relating to the implementation of TSCA. The SACC operates in accordance with the Federal Advisory Committee Act, 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. Since other entities may also be interested, the Agency has not attempted to describe all the specific entities that may be interested.

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 of this document.

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 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 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 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 draft hazard and exposure assessment documents supporting risk evaluations?

TSCA requires EPA to conduct risk evaluations on high-priority chemical substances and allows chemical manufacturers to request an EPA-conducted risk evaluation of a chemical substance (or category of chemical substances) using the procedures established in 40 CFR 702.37. TSCA also 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. 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 is EPA evaluating these chemical substances?

1,2-Dichloropropane (78-87-5), 1,1,2-trichloroethane (79-00-5), trans -1,2-dichloroethylene (156-60-5), TBBPA (79-94-7), and ethylene dibromide (106-93-4), were designated in December 2019 as high-priority substances under the Frank R. Lautenberg Chemical Safety for the 21st Century Act and are currently in the risk evaluation process. EPA published final scope documents in August 2020. The scope documents outlined the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations the Agency expected to consider in its risk evaluations. This set of chemical substances differs in commercial applications and physical chemical properties, with technical support documents informing the risk evaluation. A summary of each chemical is provided below.

• 1,2-Dichloropropane is a colorless, flammable liquid with a chloroform-like odor with a production volume in the United States between 100 million and 1 billion pounds. Industrially, 1,2-dichloropropane is manufactured as a byproduct, processed as a reactant, incorporated into formulation, mixture, or reaction products. Commercial and consumer uses of 1,2-dichloropropane include laboratory chemicals and cleaning and furnishing care products, including all-purpose liquid spray cleaner, all-purposes waxes and polishes, and all-purpose liquid cleaners and polishes.
• 1,1,2-Trichloroethane is a colorless, sweet-smelling liquid with a production volume in the United States between 100 million and 250 million pounds. 1,1,2-trichloroethane is manufactured (including imported) in the United States and used in processing as a reactant and in other processing activities such as recycling. Industrial and commercial uses include adhesives, sealants, and use as a laboratory chemical.
• Trans-1,2-dichloroethylene is a highly flammable, colorless liquid with a sharp, harsh odor with a total production volume in the United States between 1 and 10 million pounds. Trans-1,2-dichlorethylene is manufactured (including imported) in the United States and used as a reactant in processing and in other processing activities such as recycling. Commercial and consumer uses include degreasers, lubricants, solvents, and as a laboratory chemical.
• 4,4′-(1-Methylethylidene)bis[2, 6-dibromophenol] TBBPA is a crystalline solid with a total production volume in the United States between 20 million and 100 million pounds. TBBPA is imported into the United States and used as an additive and reactive chemical. As an additive flame retardant, TBBPA is incorporated into polymers via physical mixing and used in acrylonitrile-butadiene-styrene resins for electronic enclosures and electronic consumer products with an outer plastic casing. As a reactive flame retardant, TBBPA is incorporated into polymers via chemical reactions at an early stage of manufacturing and primarily used as a reactive flame retardant in epoxy resin printed circuit boards by covalently binding to epoxy and polycarbonate resins. TBBPA is found in electrical and electronic products, batteries, fabric, ( printed page 37108) textile and leather products, laboratory chemicals, and building and construction materials for commercial and consumer uses. The draft risk evaluation is available in docket ID number EPA-HQ-OPPT-2018-0462 at https://www.regulations.gov. The Agency is requesting comments on the draft risk evaluation and associated documents including the technical support documents.
• Ethylene dibromide is a volatile, water-soluble liquid with a total production volume in the United States between 1 and 20 million pounds. Ethylene dibromide is not manufactured in the United States; but is solely imported from foreign countries, and some of this is repackaged in the United States. It is used primarily in processes incorporating into formulation, mixture, or reaction products in fuels and fuel additives. It is also used in industrial processes as a reactant, commercially as a laboratory chemical. Industrial use of ethylene dibromide includes use as fuel agents in petroleum refineries, and commercial and consumer use include use in fuels and related products.

D. What is the topic of the planned SACC peer review?

EPA is soliciting comments from the SACC on a variety of charge questions related to 1,2-DCP, 1,1,2-TCA, tDCE, TBBPA, and EDB. Many of the methods and analyses used in these evaluations are not novel and have been reviewed in the development of the tools used in various Agency work products or in previous TSCA assessments. EPA is focusing peer review on critical inputs and novel approaches.

EPA is soliciting peer review from the SACC on the following documents:

1. Draft technical support document for environmental and human health hazard for 1,2-DCP;

2. Draft technical support documents for environmental and human health hazard and for exposure, including physical chemistry, fate and transport for 1,1,2-TCA;

3. Draft technical support document for environmental and human health hazard for tDCE;

4. Draft technical support documents for environmental and human health hazard and exposure for TBBPA; and

5. Draft technical support document for exposure, including physical chemistry, fate and transport for EDB. A draft technical support document for environmental and human health hazard will be made available no later than June 26, 2026. When that document is available, it will be added to this docket. Charge questions related to the EDB hazard technical support document will also be added to the docket no later than June 26, 2026.

EPA is soliciting comments on the following scientific issues:

1. Hazard identification and characterization

• EPA is requesting input on the data and methods used to evaluate cancer for 1,1,2-TCA, 1,2-DCP, and TBBPA, including evaluation of potential genotoxic and non-genotoxic carcinogenic modes of action.
• EPA is requesting input on the application of the Rethinking Carcinogenicity Assessment for Agrochemicals Project (ReCAAP) Framework for tDCE.
• EPA is soliciting comments on proposed noncancer points of departure for 1,1,2-TCA, tDCE, 1,2-DCP, EDB, and TBBPA.

2. Environmental hazard threshold estimates

• EPA is requesting input on the parameters and approaches used to estimate acute avian thresholds resulting from EDB exposure.

3. Exposure assessment and characterization

• With regards to occupational and consumer exposure estimates, EPA is requesting input on the parameters and approaches used to estimate inhalation and dermal exposure in workers and consumers for EDB from refueling small aircraft.
• With regards to environmental exposure and general population exposure estimates, EPA is soliciting feedback on the data and screening approaches used to characterize environmental and general population exposures of EDB.

3. Use of physiologically based pharmacokinetic (PBPK) modeling for human health hazard:

• EPA is requesting input on the parameters and application of PBPK modeling used to derive an inhalation point of departure via route-to-route extrapolation for human health hazards of 1,1,2-TCA.
• EPA is requesting input on the application of PBPK model with the addition of an in silico dermal sub-model to derive dermal HEDs via route-to-route extrapolation for EDB.

4. Dermal exposure modeling approaches

• EPA is requesting input on the modeling parameters and application of probabilistic dermal exposure modeling to estimate occupational exposures for 1,1,2-trichloroethane.

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 technical support documents. These public meetings are part of the SACC's peer review of the Agency's methods and novel analyses for the draft technical support documents. 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 final TSCA risk evaluations, which may inform other EPA efforts related to the assessment and regulation of the chemical substances. The Agency is seeking peer 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 meeting(s)?

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 meeting(s) and will remain open until the end of the meeting. To make oral comments during one of these meetings, follow the instructions in this document.

C. How can I access the documents?

The draft technical support documents, related technical supporting materials, and draft charge questions are available in docket ID number EPA-HQ-OPPT-2026-2246 at https://www.regulations.gov. As previously noted, the EDB hazard technical support document and related charge questions will be added to the docket no later than June 26, 2026.

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 Hazard and Exposure Assessments for 1,2-DCP, 1,1,2-TCA, tDCE, TBBPA, and EDB web page at https://www.epa.gov/​tsca-peer-review/​peer-review-evaluating-12-dcp-112-tca-tdce-tbbpa-and-edb. Although only the technical support ( printed page 37109) documents for TBBPA are part of the SACC peer review, the final Risk Evaluation for TBBPA is also available in docket ID number EPA-HQ-OPPT-2018-0462 at https://www.regulations.gov.

IV. Next Steps

After the peer review meeting, the SACC will prepare the meeting minutes and final report document summarizing its recommendations to the 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 evaluations and unreasonable risk determinations under TSCA for these chemical substances. Under TSCA, EPA must then initiate risk management actions to address the unreasonable risk if identified.

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

91 FR 37106