The U.S. Environmental Protection Agency (EPA) announced the availability of the Draft Systematic Review Protocol Supporting TSCA Risk Evaluations for Chemical Substances (Draft Protocol) on December 20, 2021. 86 Fed. Reg. 71891. According to EPA, the Draft Protocol includes a revised generic approach for Toxic Substances Control Act (TSCA)-related approaches accounting for previous peer review comments from the Science Advisory Committee on Chemicals (SACC) reviews of risk evaluations on the first ten chemical assessments and more recent recommendations from the National Academies of Sciences, Engineering, and Medicine (NASEM) review of the Application of Systematic Review in TSCA Risk Evaluations. EPA states that in addition to the revised, generic approach, the peer review package will include appendices containing chemical-specific information that is relevant for search strings and screening statements and data evaluation criteria for the next chemical risk evaluations being conducted by the Office of Pollution Prevention and Toxics (OPPT). The Draft Protocol provides specific details of the systematic reviews for the individual chemicals listed below:

• o-Dichlorobenzene

• p-Dichlorobenzene

• 1,2-Dichloroethane

• trans-1,2- Dichloroethylene

• 1,1,2-Trichloroethane

• 1,2-Dichloropropane

• 1,1-Dichloroethane

• Ethylene dibromide

• 1,3-Butadiene

• 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB)

• 4,4'-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA)

• Tris(2-chloroethyl) phosphate (TCEP)

• Phosphoric acid, triphenyl ester (TPP)

• Formaldehyde

• Phthalic anhydride

• Dibutyl phthalate (DBP) (1,2-Benzene-dicarboxylic acid, 1,2- dibutyl ester)

• Butyl benzyl phthalate (BBP) -- 1,2-Benzene-dicarboxylic acid, 1-butyl 2(phenylmethyl) ester

• Di-ethylhexyl phthalate (DEHP) -- (1,2-Benzene-dicarboxylic acid, 1,2-bis(2-ethylhexyl) ester)

• Di-isobutyl phthalate (DIBP) -- (1,2-Benzene-dicarboxylic acid, 1,2-bis-(2-methylpropyl) ester)

• Dicyclohexyl phthalate

• Diisodecyl phthalate (DIDP)

• Diisononyl phthalate (DINP)

• Octamethylcyclotetra-siloxane (Cyclotetrasiloxane, 2,2,4,4,6,6,8,8-octamethyl-) (D4)

• Asbestos 2 (including Libby Amphibole Asbestos [LAA] and its tremolite, winchite, and richterite constituents)

• 1,4-Dioxane supplement

EPA invites the public to provide input on the Draft Protocol via Docket No. EPA-HQ-OPPT-2021-0414. Comments are due February 18, 2022.
SACC will hold a virtual three-day peer review public meeting to consider and review the Draft Protocol on April 19-21, 2022. Stakeholders must register online to receive the webcast meeting link and audio teleconference information. Registration instructions will be announced on the SACC website by early March 2022. After the public meeting, SACC will prepare meeting minutes summarizing its recommendations to EPA. The meeting minutes will be posted on the SACC website and in the relevant docket.