The regulation of per- and polyfluoroalkyl substances (PFAS), or “forever chemicals,” was a focal point for the Biden administration. In April 2024, the administration, through the U.S. Environmental Protection Agency (EPA), issued two key PFAS rules. The first set nationwide drinking water standards, or maximum contaminant levels (MCLs), for six types of PFAS, and the second designated PFOA and PFOS, and their salts and structural isomers, as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Both rules are currently being challenged in court, although no judicial stays were requested or are in place.