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Draft Scope Documents for Chemicals Undergoing Risk Evaluation Available for Public Comment

For Release: April 6, 2020

EPA is asking for public input on the first set of draft scope documents for the next group of chemicals undergoing risk evaluation under the Toxic Substances Control Act (TSCA). These chemicals were designated as a high-priority for risk evaluation in December 2019, and seeking public input on the conditions of use to be included in the risk evaluations for these chemicals is the next step in the process outlined in TSCA. It is important to note that being designated as a high-priority chemical does not mean that a chemical is high risk.

EPA is releasing draft scope documents for 13 of the next 20 chemicals undergoing risk evaluation. The scope documents include the proposed conditions of use, hazards, exposures, and the potentially exposed or susceptible subpopulations the EPA expects to consider in the risk evaluations. The documents also include: a description of the reasonably available information and the science approaches that the agency plans to use, a conceptual model that outlines the potential hazards and exposures throughout the life cycle of the chemical, an analysis plan to identify the approaches and methods EPA plans to use to assess health and environmental factors, and a potential plan for peer review.

Upon publication of the Federal Register notice, EPA will accept comments on these 13 draft scopes for 45 days. Comments may be submitted to the docket relevant to this action (EPA-HQ-OPPT-2019-0131), or to the individual dockets for each of the chemicals. EPA will use feedback received from the public comment process to inform the final scope documents.

Additionally, the agency will soon release and accept public comments on the seven remaining draft scope documents.

View the list of chemicals undergoing risk evaluation under TSCA and related documents:


TSCA required EPA to designate 20 chemicals as high-priority for risk evaluation. EPA finalized this list of 20 chemicals in December 2019. Finalizing this list of high-priority chemicals for risk evaluation was the final step in the prioritization process outlined in TSCA. The next steps for these chemicals are outlined in TSCA’s process for risk evaluation and includes taking public comment on scope documents for each of these 20 chemicals. 

The draft scope documents for the following 13 chemicals are available for public comment:

  1. 1,3-Butadiene, CASRN 106-99-0, Docket ID number: EPA-HQ-OPPT-2018-0451
  2. o-Dichlorobenzene (Benzene, 1,2-dichloro-), CASRN 95-50-1, Docket ID number: EPA-HQ-OPPT-2018-0444
  3. p-Dichlorobenzene (Benzene, 1,4-dichloro-), CASRN 106-46-7, Docket ID number: EPA-HQ-OPPT-2018-0446
  4. 1,1-Dichloroethane, CASRN 75-34-3, Docket ID number: EPA-HQ-OPPT-2018-0426
  5. 1,2-Dichloroethane, CASRN 107-06-2, Docket ID number: EPA-HQ-OPPT-2018-0427
  6. trans-1,2- Dichloroethylene (Ethene, 1,2-dichloro-, (1E)-), CASRN 156-60-5, Docket ID number: EPA-HQ-OPPT-2018-0465
  7. 1,2-Dichloropropane, CASRN 78-87-5, Docket ID number: EPA-HQ-OPPT-2018-0428
  8. Ethylene dibromide (Ethane, 1,2-dibromo-), CASRN 106-93-4, Docket ID number: EPA-HQ-OPPT-2018-0488
  9. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB), CASRN 1222-05-5, Docket ID number: EPA-HQ-OPPT-2018-0430
  10. 4,4'-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA), CASRN 79-94-7, Docket ID number: EPA-HQ-OPPT-2018-0462
  11. Phosphoric acid, triphenyl ester (TPP), CASRN 115-86-6, Docket ID number: EPA-HQ-OPPT-2018-0458
  12. 1,1,2-Trichloroethane, CASRN 79-00-5, Docket ID number: EPA-HQ-OPPT-2018-0421
  13. Tris(2-chloroethyl) phosphate (TCEP) (Ethanol, 2-chloro-, 1,1',1''-phosphate), CASRN 115-96-8, Docket ID number: EPA-HQ-OPPT-2018-0476