1,3-Butadiene; Draft Risk Evaluation Under the Toxic Substances Control Act (TSCA); Science Advisory Committee on Chemicals (SACC) Peer Review; Request for Nominations of ad hoc Peer Reviewers

<NOTICE> ENVIRONMENTAL PROTECTION AGENCY <DEPDOC>[EPA-HQ-OPPT-2024-0425; FRL-12241-01-OCSPP]</DEPDOC> <SUBJECT>1,3-Butadiene; Draft Risk Evaluation Under the Toxic Substances Control Act (TSCA); Science Advisory Committee on Chemicals (SACC) Peer Review; Request for Nominations of ad hoc Peer Reviewers</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Notice. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA or the Agency) is seeking nominations of scientific and technical experts that EPA can consider for service as <E T="03">ad hoc</E> peer reviewers assisting the Science Advisory Committee on Chemicals (SACC) with the peer review of the draft risk evaluation for 1,3-butadiene conducted under the Toxic Substances Control Act (TSCA). To facilitate nominations, this document provides information about the SACC, the intended topic for the planned peer review, the expertise sought for this peer review, instructions for submitting nominations to EPA, and the Agency's plan for selecting the <E T="03">ad hoc</E> peer reviewers for this peer review. EPA is planning to convene a virtual public meeting of the SACC in early 2025 to review the draft risk evaluation. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> Submit your nominations on or before October 18, 2024. </DATES> <HD SOURCE="HED">ADDRESSES:</HD> Submit your nomination via email to <E T="03">SACC@epa.gov</E> 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 Official to obtain special instructions before submitting that information. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> The Designated Federal Official is Alie Muneer, Mission Support Division (7602M), Office of Program Support, Office of Chemical Safety and Pollution Prevention, Environmental Protection Agency; telephone number: (202) 564-6369 or call the main office at (202) 564-8450; email address: <E T="03">muneer.alie@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">I. General Information</HD> <HD SOURCE="HD2">A. What action is the Agency taking?</HD> The Agency is seeking public nominations of scientific and technical experts that EPA can consider for service as <E T="03">ad hoc</E> peer reviewers for the SACC peer review of the draft risk evaluation for 1,3-butadiene. EPA will be soliciting comments from the experts on the approach and methodologies utilized in the draft risk evaluation. This document provides instructions for submitting such nominations for EPA to consider for the SACC peer review. EPA will publish a separate document in the <E T="04">Federal Register</E> in the fall of 2024 to announce the availability of the draft risk evaluation and solicit public comments. The public comments received during the public comment period for the draft risk evaluation material will be provided to the SACC and <E T="03">ad hoc</E> peer reviewers. <HD SOURCE="HD2">B. What is the Agency's authority for taking this action?</HD> The SACC operates in accordance with TSCA section 26(o), 15 U.S.C. 2625(o) and the Federal Advisory Committee Act (FACA), 5 U.S.C. 10, to provide independent advice and expert consultation with respect to the scientific and technical aspects of issues relating to the implementation of TSCA, 15 U.S.C. 2601 <E T="03">et seq.,</E> the Pollution Prevention Act (PPA), 42 U.S.C. 13101 <E T="03">et seq.,</E> and other applicable statutes. <HD SOURCE="HD2">C. Does this action apply to me?</HD> 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 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. <HD SOURCE="HD1">II. Background</HD> <HD SOURCE="HD2">A. What is the purpose of the SACC?</HD> 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 T="03">e.g.,</E> 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 20 members. When needed, the committee will be assisted by <E T="03">ad hoc</E> peer reviewers with specific expertise in the topics under consideration. <HD SOURCE="HD2">B. Why is EPA conducting these risk evaluations?</HD> TSCA requires EPA to conduct risk evaluations on prioritized 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 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 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 the TSCA risk evaluation process for existing chemicals ( <E T="03">i.e.,</E> prioritization, risk evaluation, and risk management), go to <E T="03">https://www.epa.gov/assessing-and-managing-chemicals-under-tsca.</E> <HD SOURCE="HD2">C. Why is EPA evaluating the risks from 1,3-butadiene?</HD> In December 2019, EPA designated 1,3-butadiene (CASRN 106-99-0) as a high-priority substance for risk evaluation following the prioritization process as required by Section 6(b) of TSCA and implementing regulations (40 CFR part 702) (Docket ID: EPA-HQ-OPPT-2019-0131). 1,3-Butadiene (CASRN 106-99-0) is a volatile, colorless gas with a total U.S. production volume between 1 and 5 billion pounds. It is produced in petrochemical processing and extracted and further processed as a building block for several polymers and elastomers that do not readily depolymerize. Air is expected to be the major pathway of exposure for 1,3-butadiene in the environment. Although 1,3-butadiene is moderately soluble in water, monitoring data indicate that it is not detected in water. Environmental release data show that more than 98 percent of 1,3-butadiene facility releases are to air. Once in air, 1,3-butadiene will not deposit to land or adsorb to organic matter. Long-range transport in air is not expected, in part, because 1,3-butadiene has a short half-life (<8 hours) and will degrade into formaldehyde and acrolein. Reduced fetal body weight and hematological effects are indicated as the most sensitive and robust non-cancer human health hazards. EPA has previously classified 1,3-butadiene as a human carcinogen and epidemiology studies have demonstrated an association between 1,3-butadiene exposure and increased incidence of leukemia in workers. EPA will be submitting the draft risk evaluation of 1,3-butadiene and associated supporting documents for external peer review. The draft risk evaluation will include analyses of physical-chemical properties, the fate and transport in the environment, releases to the environment, exposure to workers and the general population, including potentially exposed or susceptible subpopulations, environmental risk characterization, and human health hazard and risk characterization for workers and the general population. <HD SOURCE="HD2">D. What is the topic of the planned SACC peer review?</HD> EPA is focusing its charge to the SACC on methods and analyses that are novel and have not been reviewed in other venues. Methods and analyses used in this risk evaluation that are not novel, have been reviewed during development of the tools, used in previously reviewed agency work products, or used in previous TSCA assessments ( <E T="03">e.g.,</E> systematic review, BMDS, etc.) are not included in the charge questions. Feedback from this review will be considered in the development of the final risk evaluation for 1,3-butadiene under TSCA. Specifically, EPA will be seeking comment on the issues below: • No exposure to aquatic and terrestrial species is expected due to the physical and chemical properties of 1,3-butadiene, which is primarily released to air and does not partition, deposit, or persist in or on water or soil. Monitoring data indicate that 1,3-butadiene is not detected in water. Exposure of terrestrial organisms via ambient air will be brief due to the reactive nature of 1,3-butadiene. EPA will be seeking comment on the qualitative risk assessment for ecological taxa for 1,3-butadiene. • 1,3-Butadiene photodegrades with a half-life ranging from 1.6-2.6 hours to form formaldehyde and acrolein when it reacts with hydroxyl radicals in the atmosphere. Because non-cancer health effects of formaldehyde and acrolein are dissimilar to 1,3-butadiene non-cancer health effects, risks will not be combined ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 19k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━