On September 4, 2020, the U.S. Environmental Protection Agency (EPA) published two Federal Register notices regarding the risk evaluations for the 20 high-priority chemicals designated in December 2019. In the first notice, EPA announced the availability of the final scope documents for the risk evaluations to be conducted under the Toxic Substances Control Act (TSCA) for the 20 high-priority substances. 85 Fed. Reg. 55281. The scope document for each chemical substance includes the conditions of use (COU), hazards, exposures, and the potentially exposed or susceptible subpopulations (PESS) that EPA plans to consider in conducting the risk evaluation for the chemical substance. In the second notice, EPA announced the availability of the final list identifying manufacturers subject to fee obligations for EPA-initiated risk evaluations under TSCA Section 6. 85 Fed. Reg. 55283. We will supplement this memorandum next week after we have reviewed the scopes in detail.
Final Scope Documents
As reported in our December 20, 2019, memorandum, EPA published the final list of high-priority chemicals on December 20, 2019. The 20 chemicals consist of seven chlorinated solvents, six phthalates, four flame retardants, formaldehyde, a fragrance additive, and a polymer precursor:
| Chemical Substance | Chemical Abstracts Service (CAS) Registry Number (RN) | Docket ID Number |
| 1,3-Butadiene | 106-99-0 | EPA-HQ-OPPT-2018-0451 |
| o-Dichlorobenzene (Benzene, 1,2-dichloro-) | 95-50-1 | EPA-HQ-OPPT-2018-0444 |
| p-Dichlorobenzene (Benzene, 1,4-dichloro-) | 106-46-7 | EPA-HQ-OPPT-2018-0446 |
| 1,1-Dichloroethane | 75-34-3 | EPA-HQ-OPPT-2018-0426 |
| 1,2-Dichloroethane | 107-06-2 | EPA-HQ-OPPT-2018-0427 |
| trans-1,2-Dichloroethylene (Ethene, 1,2-dichloro-, (1E)-) | 156-60-5 | EPA-HQ-OPPT-2018-0465 |
| 1,2-Dichloropropane | 78-87-5 | EPA-HQ-OPPT-2018-0428 |
| Ethylene dibromide (Ethane, 1,2-dibromo-) | 106-93-4 | EPA-HQ-OPPT-2018-0488 |
| 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta [g]-2-benzopyran (HHCB) | 1222-05-5 | EPA-HQ-OPPT-2018-0430 |
| 4,4′-(1-Methylethylidene)bis[2, 6-dibromophenol] (TBBPA) | 79-94-7 | EPA-HQ-OPPT-2018-0462 |
| Phosphoric acid, triphenyl ester (TPP) | 115-86-6 | EPA-HQ-OPPT-2018-0458 |
| 1,1,2-Trichloroethane | 79-00-5 | EPA-HQ-OPPT-2018-0421 |
| Tris(2-chloroethyl) phosphate (TCEP) (Ethanol, 2-chloro-, 1,1′,1″-phosphate) | 115-96-8 | EPA-HQ-OPPT-2018-0476 |
| Butyl benzyl phthalate (1,2-Benzenedicarboxylic acid, 1- butyl 2-(phenylmethyl) ester) | 85-68-7 | EPA-HQ-OPPT-2018-0501 |
| Dibutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- dibutyl ester) | 84-74-2 | EPA-HQ-OPPT-2018-0503 |
| Dicyclohexyl phthalate | 84-61-7 | EPA-HQ-OPPT-2018-0504 |
| Phthalic anhydride (1,3-Isobenzofurandione) | 85-44-9 | EPA-HQ-OPPT-2018-0459 |
| Formaldehyde | 50-00-0 | EPA-HQ-OPPT-2018-0438 |
| Di-ethylhexyl phthalate (1,2-Benzenedicarboxylic acid, 1,2- bis(2-ethylhexyl) ester) | 117-81-7 | EPA-HQ-OPPT-2018-0433 |
| Di-isobutyl phthalate (1,2-Benzenedicarboxylic acid, 1,2-bis(2-methylpropyl) ester) | 84-69-5 | EPA-HQ-OPPT-2018-0434 |
Comments were received during two 45-day comment periods following the announcement of the draft scope documents for the risk evaluations to be conducted for 13 of the 20 high-priority substances and the remaining 7 of the 20 high-priority substances. According to EPA, comments addressed the general approach to the risk evaluation process (e.g., collection, consideration, and systematic review of relevant information), the specific elements of the scope documents (e.g., hazard, exposure, and PESS), information specific to the chemical substances (e.g...
