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September 9, 2022

EPA Publishes Draft Scope Document for D4 for Public Comment

Lynn L. Bergeson Carla N. Hutton

The U.S. Environmental Protection Agency (EPA) announced on September 8, 2021, the availability of the draft scope of the risk evaluation to be conducted for octamethylcyclotetra-siloxane (D4). 86 Fed. Reg. 50347. As reported in our October 7, 2020, blog item, through the American Chemistry Council’s Silicones Environmental, Health, and Safety Center, Dow Silicones Corporation, Elkem Silicones USA Corporation, Evonik Corporation, Momentive Performance Materials, Shin-Etsu Silicones of America, Inc., and Wacker Chemical Corporation requested a risk evaluation of D4 pursuant to Section 6 of the Toxic Substances Control Act (TSCA). The draft scope document includes the conditions of use, hazards, exposures, and the potentially exposed or susceptible subpopulations that EPA plans to consider in conducting the risk evaluation for this chemical substance. EPA is also opening a 45-calendar day comment period on the draft scope to allow for the public to provide additional data or information that could be useful in preparing the final scope document. Comments are due October 25, 2021.
EPA plans to evaluate manufacturing (including importing); processing; distribution in commerce; industrial, commercial, and consumer uses; and disposal of D4 in the risk evaluation. According to the draft scope document, D4 is manufactured (including imported) in the United States. The chemical is processed as a reactant; incorporated into a formulation, mixture, or reaction product; and incorporated into articles. The draft scope document states that the identified processing activities also include the repackaging and recycling of D4. D4 is primarily used to make other silicone chemicals and as an ingredient in consumer products regulated by the Federal Food, Drug, and Cosmetic Act (FFDCA). Commercial uses include adhesives and sealants, automotive care products, paints and coatings, and other plastic and rubber products. Additional consumer uses include adhesives and sealants, automotive care products, laundry and dishwashing products, paints and coatings, and other plastic and rubber products.
EPA notes that some of these conditions of use were identified in the manufacturer request as circumstances on which EPA was requested to conduct a risk evaluation. EPA identified other conditions of use from information reported to EPA through Chemical Data Reporting (CDR), published literature, and consultation with stakeholders for both uses currently in production and uses whose production may have ceased. EPA presented the proposed additions of these EPA-identified conditions of use and the basis for these proposed additions, along with the manufacturer request, for a 45-day comment period in June 2020.