EPA is taking another step in its efforts to protect people from the health risks posed by exposure to "forever chemicals" in communities across the country. Exposure to per-and polyfluoroalkyl substances (PFAS) has been linked to cancers, impacts to the liver and heart, and immune and developmental damage to infants and children. This final rule will designate two widely used PFAS chemicals, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund, and will help ensure that polluters pay to clean up their contamination. This final action will address PFOA and PFOS contamination by enabling investigation and cleanup of these harmful chemicals and ensuring that leaks, spills, and other releases are reported. In addition to the final rule, EPA is issuing a separate CERCLA enforcement discretion policy that makes clear that EPA will focus enforcement on parties who significantly contributed to the release of PFAS chemicals into the environment, including parties that have manufactured PFAS or used PFAS in the manufacturing process, federal facilities, and other industrial parties.