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EPA Receives Manufacturer Request for Risk Evaluation Under TSCA Section 6

For Release: April 8, 2020

On March 19, 2020, EPA received a complete manufacturer request for EPA to conduct a risk evaluation of octamethylcyclotetrasiloxane (D4) from Dow Silicones Corporation, Elkem Silicones USA Corporation, Evonik Corporation, Momentive Performance Materials, Shin-Etsu Silicones of American, Inc., and Wacker Chemical Corporation (collectively, D4 Manufacturers) through the American Chemistry Council’s Silicones Environmental, Health, and Safety Center (SEHSC). D4 is used to make other silicone chemicals and as an ingredient in some personal care products. D4 was identified in the 2014 Update to the TSCA Work Plan.

Under section 6(b)(4) of the Toxic Substances Control Act, EPA issued a final rule that established a process for conducting risk evaluations to determine whether a chemical substance presents an unreasonable risk of injury to human health or the environment without consideration of costs or other non-risk factors, including an unreasonable risk to potentially exposed or susceptible subpopulations, under the conditions of use. The final rule also establishes the process and criteria for manufacturers of a chemical to request an EPA-conducted risk evaluation on the chemical for conditions of use of interest to the manufacturer.

Within 15 business days of receiving a facially complete request (i.e., submission appears to be consistent with rule requirements), EPA must notify the public of receipt of this request under 40 CFR 702.37(e)(2). Within 60 business days of receipt of a facially complete request, EPA will submit for publication the receipt of the request in the Federal Register, open a public docket for the request, and provide no less than 45 calendar days for public comment. The docket will contain the manufacturer request, EPA’s proposed additions of conditions of use, and the basis for those proposed additions. During the public comment period, the public may comment on the request as well as the additional conditions of use EPA is proposing for inclusion. After the comment period closes, the Agency has up to 60 days to either grant or deny the request to conduct a risk evaluation under 40 CFR 702.37(e)(6).

For questions concerning D4 please contact Bethany Masten at

For more information on manufacturer requests: