On September 17, 2025, EPA announced that it will retain the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) hazardous substance designation for PFOA and PFOS, two PFAS compounds. The final rule designating PFOA and PFOS (and their salts and structural isomers) as hazardous substances under CERCLA became effective on July 8, 2024. Further, EPA may require potentially responsible parties – PRPs – to clean up or pay for the cleanup of hazardous substances. (ongoing litigation, currently in abeyance, challenging the CERCLA designation of PFOA and PFOS), asking the court to lift the abeyance and propose an amended briefing schedule. Prior to its 2024 PFOA and PFOS designation, EPA’s CERCLA hazardous substance list was comprised solely of substances designated under other environmental statutes (e.g., Clean Water Act, Clean Air Act, Resource Conservation and Recovery Act, and the Toxic Substances Control Act).