Hearings, Meetings, Proceedings, etc.: 1,1 Dichloroethane and 1,2 Dichloroethane; Science Advisory Committee on Chemicals

1,1-Dichloroethane and 1,2-Dichloroethane; Science Advisory Committee on Chemicals (SACC) Peer Review; Notice of SACC Meeting, Availability of Draft Documents and Request for Comment

Dates

Preparatory Public Meeting

Meeting date: August 27, 2024, 1:00 p.m. to approximately 4:00 p.m. (EDT).

Comments: Submit written comments on the scope and clarity of the charge questions on or before noon (12:00 p.m. EDT) on August 23, 2024.

Registration: To request time to present oral comments during the preparatory meeting, you must register by noon (12:00 p.m. EDT) on August 23, 2024. For those not making oral comments, registration will remain open through the end of the meeting on August 27, 2024.

SACC Peer Review Public Meeting

Meeting dates: September 17 through 20, 2024, 10:00 a.m. to approximately 5:00 p.m. (EDT).

Comments: Submit written comments on the draft documents on or before September 3, 2024.

Registration: To request time to present oral comments during the peer review meeting, you must register by noon, September 10, 2024. For those not making oral comments, registration will remain open through the end of the meeting.

Special Accommodations: To allow sufficient time for EPA to process your request for special accommodations before the meeting, please submit the request at least ten business days in advance of the meeting.

Supplementary Information

I. Executive Summary

A. What action is the Agency taking?

EPA is announcing the availability of and soliciting public comment on the draft risk evaluation for 1,1-dichloroethane and the draft human health hazard technical support document for 1,2-dichloroethane. The draft documents were prepared under the Toxic Substances Control Act (TSCA) and will be submitted to the Science Advisory Committee on Chemicals (SACC) for peer review. EPA is also announcing that there will be two virtual public meetings of the SACC: On August 27, 2024, a preparatory meeting for the SACC to consider the scope and clarity of the draft charge questions for the peer review; and on September 17 through 20, 2024, the peer review meeting for the SACC to consider the draft documents and public comments.

This document provides instructions for accessing the materials, submitting written comments, and registering to provide oral comments and attend 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 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 (PPA), 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 in the assessment of risks involving chemical substances and mixtures regulated under TSCA (including members of at-risk communities, non-governmental organizations (NGOs), federal, state, and local officials). 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 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 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., synthetic biology, 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 prioritized 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 (COUs). These evaluations include assessing unreasonable 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 ensure 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- s.

C. Why is EPA evaluating these chemical substances?

In 2020, EPA issued final scope documents for the 20 chemical substances designated in December 2019 as High-Priority Substances for the TSCA risk evaluation process, which included 1,1-dichloroethane and 1,2-dichloroethane. The final scope documents outline the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations the Agency expected to consider in its risk evaluation for the substances (85 FR 55283, September 4, 2020 (FRL-10013-90)).

1,1-Dichloroethane (CASRN 75-34-3) is a chlorinated solvent that is manufactured and used primarily in industrial applications, such as a reactant for the manufacture of other chemicals or as a laboratory chemical. 1,2-dichloroethane (CASRN 107-06-2) is a colorless liquid, with a pleasant, chloroform-like odor, that is highly flammable and primarily used in plastic material manufacturing, specifically the manufacture of vinyl chloride. The reported total production volume of 1,1-dichloroethane in 2016 and 2020 was between 100 million and one billion pounds with a high percentage used for processing as a reactive intermediate and a small percentage used for commercial use as a laboratory chemical. The reported production volume of 1,2-dichloroethane was between 20 and 30 billion lbs/year, and a high percentage of the production volume is used for processing as a reactive intermediate in the manufacture of vinyl chloride.

Given that the largest reported environmental releases of 1,1-dichloroethane are to air, a major exposure pathway to 1,1-dichloroethane is through releases to air. Based on its physical and chemical properties including water solubility, vapor pressure, and Henry's Law Constant, 1,1-dichloroethane released to air is expected to remain primarily in air and 1,1-dichloroethane released to water will remain in water as it is water soluble. Continuous releases of 1,1-dichloroethane to water are expected to volatilize to air at rates dependent on environmental conditions, however, a portion of 1,1-dichloroethane will remain in the water column (maximum solubility is 5 g/liter). EPA, therefore, assessed relevant air, surface water, and land exposure pathways. EPA relied on databases reporting multi-year 1,1-dichloroethane releases to ambient air, surface water, and disposal to land, such as the Toxic Release Inventory (TRI), the National Emissions Inventory (NEI) and Discharge Monitoring Reports (DMR), among others, to conduct major portions of its exposure analysis.

Due to limited empirical data for human health and portions of the environmental hazard assessments, EPA relied on read-across approaches to supplement 1,1-dichloroethane data to propose hazard values. Specifically, for the human health assessment of 1,1-dichloroethane, EPA used 1,2-dichloroethane as an analog for a read-across method to supplement the non-cancer and cancer hazard information for 1,1-dichloroethane.

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

EPA is submitting the draft risk evaluation of 1,1-dichloroethane, draft human health hazard technical support document of 1,2-dichloroethane, and associated supporting documents to the SACC for peer review, along with the public comments received. The draft risk evaluation for 1,1-dichloroethane includes analyses of physical-chemical properties, the fate and transport in the environment, exposure to workers and the general population including potentially exposed or susceptible subpopulations, releases to the environment, environmental hazard and risk characterization for terrestrial and aquatic species, and human health hazard and risk characterization for workers and the general population. EPA identified 1,2-dichloroethane as an analog for reading across to 1,1-dichloroethane non-cancer and cancer human health since EPA had limited non-cancer and cancer empirical toxicity data available for 1,1- dichloroethane. EPA is therefore submitting the draft human health hazard technical support document for 1,2-dichloroethane for peer review. EPA is in the process of preparing a draft risk evaluation for 1,2-dichloroethane that will be released later for public comment and peer review. The 1,2-dichloroethane human health hazard technical support document will also accompany the 1,2-dichloroethane draft risk evaluation when it is released for public comment but will not undergo additional peer review since is currently being evaluated along with 1,1-dichloroethane.

EPA is focusing its peer review charge on specific scientific areas and analyses. Many of the methods and analyses used in these evaluations are not novel and have been reviewed in the development of previous TSCA assessments. EPA is requesting feedback on approaches, results and calculations associated with the exposure, human health hazard and environmental hazard analyses. EPA is releasing the draft risk evaluation for public comment and independent, expert peer review. Once EPA receives comment and input from public comment and peer review, revisions will be made, and the Agency will finalize the 1,1-dichloroethane risk evaluation and incorporate information from the 1,2-dichloroethane draft human health hazard technical support document into the 1,2-dichloroethane draft risk evaluation.

III. Public Meeting of the SACC

A. What is the purpose of the virtual public meeting(s)?

EPA is planning two virtual public meetings: (1) A preparatory public meeting for the SACC to consider and ask questions regarding the scope and clarity of the draft charge questions; and (2) a public peer review meeting for the SACC to consider and peer review the draft documents. These public meetings are part of the SACC's peer review of the Agency's methods and novel analyses for the draft risk evaluation of 1,1-dichloroethane and the draft human health hazard technical support document of 1,2-dichloroethane. The agenda for these meetings will be posted on the docket and will also be available through the SACC website.

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 beginning approximately one month prior to the meeting and will remain open through the end of the meeting. To make oral comments during one of these meetings, follow the instructions in this document.

Recommendations from this SACC review and public comments will be considered in the development of the TSCA risk evaluations for both chemical substances and may inform other EPA efforts related to the assessment and regulation of 1,1-dichloroethane and 1,2-dichloroethane. 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 access the documents?

The draft risk evaluation for 1,1-dichloroethane, draft human health hazard technical support document for 1,2-dichloroethane, and related documents, including background documents, related supporting materials, and draft charge questions, are available in the docket. As additional background materials become available, EPA will include those additional background materials ( e.g., SACC members and consultants participating in this meeting and the meeting agenda) in the docket and through links on the SACC website at https://www.epa.gov/tsca-peer-review .

After the public 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.

C. How can I provide comments?

To ensure proper receipt of comments, it is imperative that you identify docket ID No. EPA-HQ-OPPT-2024-0073 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 virtual public meetings are limited to 5 minutes. 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.

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