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EPA Reschedules November 2025 Peer Review Preparatory Meeting for TSCA Risk Evaluation of D4; Extends Comment Period by 15 Days

The U.S. Environmental Protection Agency (EPA) is rescheduling the virtual November 18, 2025, preparatory meeting for the Science Advisory Committee on Chemicals (SACC). The meeting will now be held virtually on December 1, 2025. This preparatory meeting allows the SACC and the public to ask questions about the scope and clarity of the draft charge questions for the draft risk evaluation for octamethylcyclotetrasiloxane (D4). Register for the December 1, 2025 preparatory meeting here. To present oral comments during the preparatory meeting, you must register by noon (12:00 p.m. EST) on November 24, 2025, and submit a written version of your oral comments by noon (12:00 p.m. EST) on November 28, 2025. 

The December 2-5, 2025, SACC peer review meeting to discuss the D4 draft risk evaluation and technical support documents has not been rescheduled at this time. Register for the December 2-5, 2025, SACC meeting here. EPA will announce any further postponements if necessary. 

 For additional information on the peer review, contact the Designated Federal Official, Dr. Alaa Kamel at kamel.alaa@epa.gov. Learn more about the peer review of the Draft Risk Evaluation for D4. 

Additionally, EPA is extending the comment period on the D4 draft risk evaluation by 15 days. Upon publication of a Federal Register notice, the comment period will close on December 2, 2025. Comments should be submitted to docket EPA-HQ-OPPT-2018-0443 on www.regulations.gov. After the agency has considered public comments and recommendations, EPA will issue a final risk evaluation that includes its determination as to whether D4 represents an unreasonable risk of injury to human health or the environment.    

View the D4 Draft Risk Evaluation.  

Chemicals under the Toxic Substances Control Act (TSCA)

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Last updated on November 10, 2025
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