Q: How does the designation of certain PFAS as Superfund hazardous substances affect environmental due diligence?
As awareness of per- and polyfluoroalkyl substances (PFAS) grows, evaluating whether these “forever chemicals” are present on a property has become essential. Failure to conduct due diligence that accounts for PFAS can now expose landowners to Superfund liability.
PFAS have been used for decades in industrial processes and consumer products. In 2024, the U.S. Environmental Protection Agency (EPA) designated two PFAS compounds—PFOA and PFOS—as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund). This designation heightens the importance of thorough, well‑planned environmental due diligence.
EPA’s rule took effect on July 8, 2024. After the change in presidential administrations, litigation challenging the designation was filed in early 2025. Although many expected the new EPA leadership to reconsider the rule, the agency announced in September that it would defend the designation. EPA has confirmed PFOA and PFOS are considered hazardous substances during the litigation.
Because CERCLA imposes strict liability—meaning liability without fault—property owners can be held responsible for cleanup costs even if they did not cause the contamination. PFAS presence can also reduce property value, complicate transactions, and trigger regulatory scrutiny.
Why Environmental Due Diligence Matters
Failing to look for and identify PFAS contamination can lead to substantial financial and legal consequences. Environmental due diligence evaluates a property for environmental liabilities before acquisition. Phase I Environmental Site Assessments (ESAs), conducted under ASTM E1527‑21, help identify “recognized environmental conditions” (RECs), and can provide certain legal protections.
Buyers relying on ESAs completed before the 2024 designation should understand that PFAS may not have been evaluated and that liability protections may not apply.
Key Components of PFAS Due Diligence
Effective PFAS due diligence, in conformance with the ASTM Standard, may include:
- Site visits and interviews
- Historical research into past property uses
- Review of Safety Data Sheets for fluorochemical indicators
- NAICS code analysis to identify industries associated with PFAS use
Know the Law is a bi-weekly column sponsored by McLane Middleton. Questions and ideas for future columns should be emailed to knowthelaw@mclane.com. Know the Law provides general legal information, not legal advice. We recommend that you consult a lawyer for guidance specific to your particular situation.