On August 18, 2026, a unanimous panel of the U.S. Court of Appeals for the D.C. Circuit upheld the 2024 designation by the U.S. Environmental Protection Agency (EPA) of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund). (See Chamber of Commerce of the United States of America, et al. v. EPA, No. 24-1193 (D.C. Cir. Aug. 18, 2026).)