/>iThe U.S. Environmental Protection Agency (EPA) announced on September 10, 2025, that it is seeking nominations of scientific and technical experts to be considered as ad hoc reviewers assisting the Science Advisory Committee on Chemicals (SACC) with the peer review of the draft risk evaluation of octamethylcyclotetrasiloxane (D4) under the Toxic Substances Control Act (TSCA). EPA states that these nominations will help it select approximately seven to eight ad hoc reviewers to assist SACC with its review. According to EPA, nominees should be scientists with sufficient professional qualifications to provide expert comments on the scientific issues for this review. Individuals nominated for this peer review meeting should have expertise in one or more of the following areas:
- Identification of hazards relevant to human health risk assessment;
- Evaluation and use of the D4 physiologically based pharmacokinetic (PBPK) model;
- Handling of uncertainties associated with exposure and release assessments;
- Characterization of bioaccumulation, bioconcentration, biomagnification, and potential trophic transfer;
- Human fish consumption for the general population and potentially exposed or susceptible subpopulations; and
- Identification of hazards relevant to ecological risk assessment.
Nominations for ad hoc reviewers should include the candidate’s name, affiliation, contact information, and must be submitted by September 25, 2025, to the Office of Chemical Safety and Pollution Prevention (OCSPP) Peer Review mailbox at ocspp-peerreview@epa.gov.
