One of the more closely watched issues surrounding per- and polyfluoroalkyl substances (PFAS) has been the fate of the US Chamber of Commerce lawsuit regarding the hazardous substance designation for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The ruling was issued on August 18, 2026.
Background of US Chamber of Commerce Challenge of CERCLA Designation
In April 2024, under the Biden Environmental Protection Agency (EPA), PFOA and PFOS were listed as hazardous substances under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). On November 4, 2024, the US Chamber of Commerce, et al., challenged the CERCLA designation of PFOA and PFOS. The legal challenge was largely focused on the cost-benefit analysis conducted by the EPA in promulgating the final rule; the ultimate issue in the case is whether EPA properly exercised its authority under CERCLA Section 102(a) to list PFOA and PFOS as hazardous substances, since they were not already designated under another environmental statute (Babst Calland).
Many observers expected the Trump EPA to overturn this designation. However, in September 2025, it was announced that the Trump Administration would not change course and would defend the CERCLA listing.
On August 18, 2026, the United States Court of Appeals for the District of Columbia Circuit denied every petition by the US Chamber of Commerce. It upheld the CERCLA designation for PFOA and PFOS.
With this ruling, there are several potential consequences for the regulated community.
While it is possible that the US Chamber of Commerce will appeal this to the United States Supreme Court, as it stands currently, both PFOA and PFOS are CERCLA hazardous substances.
CERCLA Reporting Requirements
As we outlined in our July 30, 2024, blog, under CERCLA, the Reportable Quantity or RQ for PFOA or PFOS is one pound. Accordingly, releases of either PFOA or PFOS of one pound or more within 24 hours must be reported to the National Response Center. Third parties that may be affected must also be notified of a release. Additionally, Local and State (or Tribal) Emergency Response Centers must be notified.
For businesses that still use Aqueous Film Forming Foam (AFFF), an emergency response event using AFFF could trigger the reporting requirement.
Also see “What are the release reporting requirements?”
Significant CERCLA Liability Concerns
The reporting issue aside, the CERCLA cleanup liability is the elephant in the room.
“The potentially larger concern for industrial companies, however, is CERCLA liability. Hazardous-substance status means that PFOA and PFOS can now form the basis for CERCLA response actions and cost-recovery claims. EPA may, after additional regulatory steps, compel responsible parties to undertake cleanup, while EPA, states, and private parties may potentially seek recovery of response costs under CERCLA” (Liskow).
The EPA has consistently stated that they have no intention of pursuing passive receivers of PFAS (e.g., publicly owned water and wastewater facilities, municipal landfills, agriculture from land application of biosolids, etc.). However, short of congressional action, there is nothing stopping a regulatory agency or a third party from pursuing enforcement action under CERCLA on these passive receivers.
Hogan Lovells Cadwalader wrote, “The survival of the PFOA and PFOS hazardous substances designation will likely have wide-reaching ramifications given the widespread presence of these compounds in the environment and the potential for CERCLA claims at many cleanup sites, including those that might otherwise be nearing completion. As a result of the hazardous substances designation, EPA may compel CERCLA potentially responsible parties to abate and clean up releases of PFOA and PFOS, and the federal government, States, and adversely affected private parties may pursue actions to recover cleanup costs under CERCLA from potentially responsible parties” (emphasis added).
Among those expressing concern over the ruling was the American Water Works Association. “While CERCLA is designed to force polluters to clean up contaminated sites, we remain concerned that water utilities – as passive receivers of PFAS – could be exposed to significant legal and financial liability under the act. Today’s decision underscores the urgent need for Congress to grant a specific exemption for water and wastewater utilities, protecting them from claims brought by potentially responsible parties such as PFAS manufacturers.”
For more information, see the United States Court of Appeals for the District of Columbia ruling.
What Should Companies Do Now?
While it is possible that the US Chamber of Commerce will appeal this to the United States Supreme Court, as it stands currently, both PFOA and PFOS are CERCLA hazardous substances.
In the short term, you may want to consider if you have any CERCLA reporting requirements. You may want to engage legal counsel to discuss your potential CERCLA exposure. At a minimum, we recommend that you evaluate the materials associated with your processes to identify and document those that do or do not contain PFAS and, if possible, document the means by which those PFAS leave your facility. Additionally, you might want to reexamine your Environmental Due Diligence practices to make certain that PFOA and PFOS are being considered as Recognized Environmental Conditions (i.e., All Appropriate Inquiry protection under CERCLA).
PFAS Technical and Litigation Support
If you have questions or need assistance with a PFAS-related issue, we can help. We have hands-on experience in the assessment/remediation of PFAS, and we have provided litigation support on several projects involving PFAS. For more information, contact Jeffrey Bolin, M.S., CHMM, at 248-932-0228, Ext. 125, or Matthew Schroeder, M.S., P.E., Ext. 117
Alan Hahn drafted this blog. Alan has an undergraduate degree in Environmental Studies and completed a graduate program in Environmental Management. He has worked in environmental management for more than 45 years. He has written hundreds of blogs and articles. His published work includes Michigan Lawyers Weekly, Detroiter, Michigan Forward, GreenStone Partners, Manure Manager Magazine, Progressive Dairy, and HazMat Magazine.
This blog was reviewed by Matthew Schroeder, M.S., P.E. Matt is a senior environmental engineer at Dragun Corporation. Matt has 30 years of experience with soil and groundwater remediation, vapor intrusion, and, more recently, with PFAS. Specific to PFAS, Matt has completed the ITRC PFAS Training; is a member of the Michigan PFAS Action Response Team, Treatment Technology Roundtable, and Michigan Manufacturers Association PFAS Work Group; and participated in the PFAS Environmental Professionals Symposium. Matt is a frequent speaker, author, and expert witness. See Matt’s bio.
Follow Dragun Corporation on LinkedIn, X, or Facebook.
Sign up for our monthly environmental newsletter.
Principled Foundation | Thoughtful Advice | Smart Solutions
Established in 1988