On May 8, 2024, EPA published in the Federal Register its final rule designating perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances under CERCLA. The designation of these two PFAS will thus be effective on July 8, 2024. For property acquisitions closing on or after July 8, environmental due diligence to meet CERCLA’s “all appropriate inquiries” standard for liability protection, which is typically performed via Environmental Site Assessments, will need to include consideration of PFOA and PFOS.

EPA’s final rule can be found here.