On August 18, 2026, the U.S. Court of Appeals for the District of Columbia Circuit issued its decision in Chamber of Commerce, et al. v. EPA, No. 24-1193, denying industry petitions to overturn EPA’s 2024 designation of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). PFOS and PFOA are two prevalent per- and polyfluoroalkyl substances (PFAS), synthetic compounds known colloquially as “forever chemicals” because their chemical composition is highly resistant to breaking down in the environment. The rule designating the compounds as hazardous substances has been effective since July 2024, but the D.C. Circuit’s landmark ruling confirms EPA’s broad statutory authority to expand the universe of CERCLA hazardous substances, cements PFAS as a significant potential liability, and promises to increase scrutiny on entities that have used PFAS in their operations, own legacy operations involving PFAS, or engage in transactions involving legacy use and impacts.
CERCLA in Brief
CERCLA, commonly known as the “Superfund” law, imposes liability on parties responsible for the presence of hazardous substances at a contaminated site. Pub. L. No. 96-510, 94 Stat. 2767 (1980) (codified as amended at 42 U.S.C. §§ 9601–9675). There are four categories of potentially responsible parties (PRPs): (1) current owners and operators of a contaminated facility; (2) past owners and operators at the time hazardous substances were disposed of; (3) generators and persons who arranged for the disposal or transport of hazardous substances; and (4) transporters of hazardous substances that selected the disposal site. 42 U.S.C. § 9607(a)(1)–(4). CERCLA liability is strict, joint and several, and retroactive, and defenses to liability are narrow and difficult to establish.
The designation of PFOS and PFOA as “hazardous substances” under the statute has several key implications. The rule further empowered EPA enforcement actions to force cleanups at contaminated sites. It also confirmed that parties—including government or private entities—who perform response actions to clean up PFOS and PFOA can seek cost recovery from PRPs. From an ongoing compliance perspective, the rule also required reporting for releases of PFOA or PFOS that exceed one pound. It created additional environmental due diligence implications on the front end of property transactions. And finally, the D.C. Circuit decision closes the door, absent U.S. Supreme Court review, on skepticism that the PFOS and PFOA designation would be rolled back by the courts.
The D.C. Circuit’s Core Holding: Confirming EPA’s CERCLA Section 102(a) Authority
Although the Petitioners raised several issues, the central question before the court in Chamber of Commerce was whether EPA had statutory authority under CERCLA section 102(a), 42 U.S.C. § 9602(a), to designate PFOS and PFOA as hazardous substances. That statutory section authorizes EPA to promulgate regulations that designate “elements, compounds, mixtures, solutions, and substances which, when released into the environment may present substantial danger to the public health or welfare or the environment” as hazardous substances under CERCLA. EPA used that authority to promulgate just such a rule in 2024. The 2024 rulemaking represented a novel regulatory approach because it was the first time EPA had exercised its standalone Section 102(a) designation authority in the more than four decades since CERCLA’s enactment.
Petitioners, led by the Chamber of Commerce and several industry trade groups, argued that EPA had to demonstrate that substantial danger will occur upon a release to the environment of PFOS or PFOA, not merely that it may occur. The court rejected that argument, holding that “may” carries its ordinary meaning of possibility and contingency, and that Congress deliberately chose probabilistic language suited to a regulatory framework built on evolving scientific evidence. The court also held that the “substantial danger” qualifier provides meaningful limits in that the risk must be “serious and real, not hypothesized,” but that PFOS and PFOA clearly satisfy that standard given the volume of peer-reviewed research linking them to serious health harms.
The bottom line is unambiguous: EPA’s designation of PFOS and PFOA as hazardous substances under CERCLA stands. The court also paved the way for future exercise of EPA’s Section 102(a) authority to add other emerging contaminants (including other PFAS compounds) to the list of CERCLA hazardous substances.
High-Risk Sectors: When to Pay Attention
Under the now-confirmed rule, PFOS and PFOA must be approached with the same gravity and care as other conventional legacy contamination issues. There is no one-size-fits-all approach and a broad cross-section of industries are potentially impacted by the regulatory listing.
Real estate and commercial lending professionals across all sectors should understand and adapt standard protocols for evaluating PFAS because the hazardous substance designation may change the environmental risk profile of commercial and industrial properties and could require updated environmental site assessments.
Parties to real estate and corporate transactions should consult with knowledgeable environmental counsel on how best to evaluate and address PFOS and PFOA in the transactional context. Potential considerations include:
- Due diligence: Updating due diligence protocols, including Phase I environmental site assessment practices, to include PFAS-specific evaluations as warranted by the context
- Contracting: Addressing PFAS liability through various means including indemnification provisions, environmental representations and warranties, and purchase price adjustment mechanisms
- Insurance: Evaluating existing and available insurance coverage to address historical liabilities and protect against potential future claims
Releases of PFOS or PFOA may trigger regulatory obligations with federal, state, and local implications.
Parties should proceed carefully to evaluate whether or how to elevate potential liabilities associated with the broader set of PFAS, but especially PFOS and PFOA. Because PFAS are ubiquitous in the environment from decades of use and intentional or inadvertent disposal, if you go looking for them, you may just find them—and not every context will warrant, for example, intrusive sampling such as in a Phase II environmental site assessment.
While the list of impacted sites and potential contributors of PFAS in the environment is ever-growing, the following sectors and business contexts may carry elevated risk and may therefore warrant heightened attention:
- Properties near airports, military bases, and fire training facilities where aqueous film-forming foam (AFFF) has historically been used in firefighting and emergency response training
- Companies that have manufactured, used, or stored AFFF, including industrial facilities, petroleum terminals, and chemical plants
- Wastewater treatment facilities and landfills that have received PFAS-laden influent or accepted PFAS-containing waste streams (EPA did acknowledge in the rulemaking process that existing liability limitations, including protections for de minimis and de micromis contributors, may temper exposure for passive receivers)
- Mining operations utilizing PFAS-based surfactants
- Winter sporting facilities where PFAS compounds may be present through wax, fabric treatments, and onsite AFFF systems
- Properties where AFFF has been used for conventional firefighting
- Car washes
- Land application of biosolids
- Building fire suppression systems containing AFFF
The Patchwork of State PFAS Restrictions
The D.C. Circuit’s decision upholding the PFOS and PFOA CERCLA designation does not exist in a vacuum. A growing number of states have enacted their own bans or restrictions on PFAS in consumer products, firefighting foam, and industrial applications. Colorado, for example, has prohibited the sale of products containing intentionally added PFAS across a wide range of categories, including food packaging, carpets, cosmetics, cookware, ski wax, and textile furnishings, with additional product categories phasing in through 2028. Colo. Rev. Stat. §§ 25-15-601 to -606. Maine’s near-total ban on intentionally added PFAS in consumer products takes effect January 1, 2030. Me. Rev. Stat. Ann. tit. 38, § 1614. Minnesota’s “Amara’s Law” extends to all products by January 1, 2032, unless the use is deemed “currently unavoidable.” Minn. Stat. § 116.943. Several other states have adopted or are considering similar restrictions, and most states have banned or restricted PFAS-containing Class B firefighting foam.
However, there is no uniform federal ban on PFAS in products, and many states have no restrictions at all. The result is a patchwork in which PFAS-containing products remain widely available in commerce even as the CERCLA designation imposes potential cleanup liability for the most prevalent of those substances. The gap between permissible product use and environmental liability exposure is narrowing.
Looking Ahead
Following the D.C. Circuit’s decision, there will be an increase in EPA enforcement and private cost-recovery actions related to PFOS and PFOA. Companies across affected sectors should not wait for site-specific enforcement or other legal action to begin evaluating potential exposure. Proactive steps, including environmental audits, contractual protections in transactions, and insurance coverage review may be advisable to help manage evolving PFAS liabilities.
Parties should contact experienced environmental legal advisors and consultants knowledgeable about PFAS to determine the proper path for addressing sites that are suspected of potential contamination. Anyone with questions about how this new ruling affects their operations or pending transactions is welcome to contact the authors.