FAQs: What EPA’s Designation of PFOA and PFOS as CERCLA Hazardous Substances Means for EPA’s Brownfields and Land Revitalization Program

These FAQs provide background information on EPA's designation of PFOA and PFOS as hazardous substances under CERCLA, and how this designation impacts liability protections at brownfield sites. FAQs listed below are for informational purposes and are applicable only to EPA's Brownfields and Land Revitalization Program.

1. What actions did EPA take?

On April 17, 2024, the U.S. Environmental Protection Agency announced the designation of two types of PFAS - perfluorooctanoic acid and perfluorooctanesulfonic acid, including their salts and structural isomers - as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act. On September 17, 2025, EPA announced its intent to retain this designation.

Explore PFAS

What are PFAS?
Per- and polyfluoroalkyl substances – known as PFAS – are a group of manufactured chemicals that have been used in industry and consumer products since the 1940s because of their useful properties. Due to their widespread production and use, as well as their ability to move and persist in the environment, PFAS can be present in water, soil, air, and food as well as in materials found in homes or workplaces.


What are PFOA and PFOS?
Perfluorooctanoic Acid and Perfluorooctane Sulfonate are subsets of PFAS known as perfluorinated alkyl acids. PFOA and PFOS are two of the most widely used and studied chemicals in the PFAS group.

 
Why is EPA concerned about PFOA and PFOS?
Due to widespread use and persistence in the environment, many PFAS – including  PFOS and PFOA (pdf) (167.21 KB, November 2017, EPA 505-F-17-001)  – are found in the blood of people and animals all over the world and are present at low levels in the environment. Further, scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals; including cancers, impacts to the liver and heart, and immune and developmental damage to infants and children.

 
PFOA and PFOS, over long periods of time, will continue to migrate in the environment; further exacerbating exposure risk and potential cleanup costs. 
 

2. Are PFOA and PFOS still hazardous substances even though the rule is in litigation? 

Yes. Even though the underlying rule is in litigation, PFOA and PFOS are currently hazardous substances under CERCLA. 

3. How does the designation of PFOA and PFOS as hazardous substances under CERCLA impact liability protections at brownfield sites? 

The designation of PFOA and PFOS as hazardous substances does not change CERCLA’s liability framework and does not automatically assign legal liability to property owners with PFOA or PFOS contamination. However, the designation does mean that a grant recipient must establish liability protection for any release of PFOA or PFOS at a Brownfield site. For example, All Appropriate Inquiries investigations conducted on a Brownfield site must now consider conditions indicative of releases or threatened releases of PFOA and PFOS to establish liability protection under CERCLA.

4. Does EPA's PFOA and PFOS hazardous substance designation change whether Brownfields funding could be used to address PFOA and PFOS? 

No. The inclusion of PFOA and PFOS – including their salts and structural isomers – as “hazardous substances” under CERCLA does not change whether EPA Brownfields and Land Revitalization Program resources can be used to address PFOA and PFOS.

Prior to being designated as CERCLA hazardous substances, PFOA and PFOS fell within the CERCLA definition of “pollutants and contaminants.” Since the definition of a “brownfield site” per CERCLA § 101(39) [1] includes sites contaminated by a “hazardous substance, pollutant, or contaminant,” EPA's Brownfields Grant funding could already be used to assess and clean up PFOA and PFOS contamination at brownfield sites.

Now that PFOA and PFOS are designated as CERCLA hazardous substances, Brownfields Grant recipients who wish to use funding to assess and cleanup sites with PFOA or PFOS must demonstrate that they cannot be held potentially liable under CERCLA § 107 for the contamination at the brownfield site.

5. Are entities which are potentially responsible for PFOA or PFOS contamination, or continued releases, eligible for Brownfields Grant funding? 

No. Entities which are potentially responsible parties for PFOA or PFOS contamination, or the continued release of either of these hazardous substances, are not eligible to receive or benefit from Brownfields Program funding (including for assessment and cleanup of brownfield sites). 

Brownfields Grant applicants who demonstrate that they are not potentially liable for the previous contamination of PFOA or PFOS (or any other hazardous substance) at the property to be addressed with funding must also comply with “continuing obligations,” per CERCLA § 101(40)(B), including “stopping any continuing releases” of any hazardous substance after acquiring the property. Read more information on CERCLA liability defenses and “Continuing Obligations." 

6. Does EPA's PFOA and PFOS hazardous substance designation impact screening or cleanup levels of PFOA and PFOS at brownfield sites? 

No. States and Tribal Nations remain the regulatory entities that oversee brownfield site assessment and cleanups of PFOA and PFOS. EPA will refer to State or Tribal Response Programs for screening and cleanup levels for PFOA and PFOS at brownfield sites. 

7. Where can I find more resource about these changes? 

[1] CERCLA § 101(39) defines a “Brownfield Site” as: “...real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.” This means that EPA’s Brownfields Grant funding can be used to clean up any substance identified as a CERCLA hazardous substance, pollutant, or contaminant. 

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Last updated on December 5, 2025