On May 27, 2025, the U.S. Department of Defense (DOD) issued a request for information (RFI) to gather information to identify and assess critical applications for DOD and the defense industrial base (DIB) that necessitate the use of existing chemicals undergoing the U.S. Environmental Protection Agency’s (EPA) Toxic Substances Control Act (TSCA) Section 6 risk evaluation process. The RFI states that it will help the Office of the Assistant Secretary of Defense for Energy, Installations, and Environment (OASD (EI&E)) Chemical and Material Risk Management Program (CMRMP) better understand the use of TSCA existing chemicals in products leading into the defense supply chain. The RFI is focused on receiving information related to the following existing chemicals:
- 1,3-Butadiene (Chemical Abstracts Service Registry Number® (CAS RN®)106-99-0);
- 1,1-Dichloroethane (CAS RN 75-34-3);
- 1,2-Dichloroethane (CAS RN 107-06-2);
- Butyl benzyl phthalate (1,2-benzene-dicarboxylic acid, 1-butyl 2(phenylmethyl) ester) (BBP) (CAS RN 85-68-7);
- Dibutyl phthalate (1,2-benzene- dicarboxylic acid, 1,2- dibutyl ester) (DBP) (CAS RN 84-74-2);
- Dicyclohexyl phthalate (DCHP) (CAS RN 84-61-7);
- Di-ethylhexyl phthalate (1,2-benzene-dicarboxylic acid, 1,2-bis(2-ethylhexyl) ester) (DEHP) (CAS RN 117-81-7);
- Di-isobutyl phthalate (1,2-benzene-dicarboxylic acid, 1,2-bis-(2methylpropyl) ester) (DIBP) (CAS RN 84-69-5);
- Di-isodecyl phthalate (1,2-benzenedicarboxylic acid, 1,2-diisodecyl ester) (DIDP) (CAS RNs 26761-40-0; 68515-49-1);
- Diisononyl phthalate (1,2-benzenedicarboxylic acid, 1,2-diisononyl ester) (DINP) (CAS RNs 28553-12-0; 68515-48-0); and
- Octamethylcyclotetra-siloxane (D4) (CAS RN 556-67-2).
DOD seeks to understand better applications that require the use of these chemicals and the criticality of these chemicals for industry and supply. The RFI notes that DOD will continue to issue RFIs to consider additional TSCA chemicals. Responses are due June 20, 2025.