Try as we may to NOT talk about per- and polyfluoroalkyl substances (PFAS), this group of chemicals continues to dominate environmental regulatory developments. PFAS are also the subject of proposed legislation and litigation, and we are still debating what PFAS are and what PFAS are not.
The PFAS CERCLA Designation
In our September 22, 2025, blog, we discussed the surprising move when the Environmental Protection Agency (EPA) decided to defend the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) designation for perfluorooctanoic acid (PFOA) and perfluorooctanoic acid (PFOS). On November 4, 2024, the US Chamber of Commerce, et al., challenged the CERCLA designation.
Status of the challenge from Babst Calland: “After briefing concluded, oral argument was held before a panel of three D.C. Circuit judges on January 20, 2026. Although the parties’ oral arguments largely focused on the cost-benefit analysis conducted by 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. The court is likely to issue an opinion sometime later this year.”
One of the many concerns that have been raised regarding the CERCLA listing is how it will affect “passive receivers” of PFAS, such as municipal wastewater treatment plants, landfills, and farms that applied biosolids. In an April 19, 2024, memo, the EPA stated that the agency will use “enforcement discretion” and will not focus on passive receivers of PFAS. However, this assurance does not preclude third-party lawsuits or state-enforcement actions. See our June 4, 2024, blog, CERCLA and PFAS – EPA’s Enforcement Discretion.
The resolution of the CERCLA designation will be closely followed this year.
PFAS TSCA Reporting
In our October 5, 2023, blog (PFAS TSCA Rule – “A Significant Regulatory Action”), we discussed the new Toxic Substance Control Act (TSCA) Recordkeeping Requirements. The EPA estimated that approximately 97% of all firms potentially affected by this rule would meet the SBA’s standard of small business, for a total of 128,051 affected small entities.
On November 10, 2025, a pre-publication notice was issued that proposed several changes to the rule, including categorical exemptions and a revised reporting timeline.
There is plenty of PFAS regulatory dust to settle in 2026, and how these issues are resolved will be very consequential for the regulated community.
Reporting Deadlines
The EPA amended the data submission period for TSCA-PFAS reporting rule by changing the start date for submissions and making corresponding changes to the end dates for the submission period; i.e., the data submission period begins on April 13, 2026, and ends on October 13, 2026, with an alternate end date for small manufacturers reporting exclusively as article importers of April 13, 2027 (see the Federal Register, May 13, 2025).
Challenging the Changes
From Winston’s Environmental Law Update, “Environmental groups and a coalition of 15 state attorneys general have signaled potential litigation challenging EPA’s November 2025 proposed rule, arguing the proposed rollbacks are unlawful under the 2020 National Defense Authorization Act mandate, as codified in TSCA Section 8(a)(7), and are arbitrary and capricious.”
While this creates more uncertainty, those affected by this rule should prepare to comply with the reporting obligation.
Approved Pesticides with PFAS…or Not
One of the areas that the EPA has focused on is addressing the backlog of new pesticides waiting for approval. The EPA has proposed registering four pesticides since April 2025: cyclobutrifluram, diflufenican, isocycloseram, and trifludimoxazin.
There is concern by some that the four pesticides pending approval contain PFAS. From Chemical Engineering and News (CE&N), “All four pesticides contain a fully fluorinated methyl or methylene group, raising concerns that they will persist in soil and water for many years.”
Nathan Donley, Environmental Health Science Director at the Center for Biological Diversity, is quoted as saying, “The proposed pesticide active ingredients can degrade into trifluoroacetic acid (TFA), which persists in the environment for more than 100 years.”
Definition of PFAS
At issue is what constitutes a PFAS. The definitions are varied and abundant.
In 2023, the EPA’s Office of Pollution Prevention and Toxics officially defined PFAS (after conducting a comprehensive public rulemaking process) as chemicals containing two or more fluorinated carbons. Therefore, under the EPA’s definition, the four proposed pesticides are not considered to be PFAS
However, the EPA’s Office of Pesticide Programs considers PFAS to be chemicals containing at least two saturated, fully fluorinated carbons, either CF2 or CF3. The Organisation for Economic Co-operation and Development (OECD) defines PFAS as any chemical with at least one saturated CF2 or CF3. The European Union has adopted a definition that is closer to that recommended by the OECD (Source: CE&N).
According to the EPA, TFA is a well-studied non-PFAS. TFA is found naturally – over 200 million tonnes are in the oceans, and it is also formed as a by-product of the degradation of some HFCs (hydrofluorocarbons) and HFOs (Hydrofluoroolefins) (Source: The European FluoroCarbons Technical Committee is a Cefic Sector Group).
On November 25, 2025, the EPA issued a Press Release, “FACT CHECK: EPA Debunks False Claims that Agency Recently Approved ‘Forever Chemical’ Pesticides.” In this document, the EPA states that “BOTTOM LINE: EPA-Approved Single Fluorinated Compounds Are NOT Forever Chemicals and Pose No Safety Concerns When Used According to Label Instructions.”
Legislation Introduced to Classify PFAS as HAPs
Finally, on December 22, 2025, bipartisan legislation was introduced that would classify certain PFAS as Hazardous Air Pollutants (HAPs) under the Clean Air Act.
The legislation is titled, “Prevent Release of Toxics Emissions, Contamination, and Transfer Act of 2026’’ or the ‘‘PROTECT Act of 2026.’’
The PROTECT Act would:
- Require the EPA to officially classify certain PFAS as hazardous air pollutants under the Clean Air Act.
- Identify industries and facilities that release PFAS into the air.
- Begin setting enforceable limits on PFAS air pollution from major sources.
- Strengthen cleanup responsibility and public reporting when PFAS are released into the environment.
Also see our blog, PFAS from Landfill Gases and Recent PFAS Developments Relating to Agriculture.
There is plenty of PFAS regulatory dust to settle in 2026, and how these issues are resolved will be very consequential for the regulated community.
PFAS Technical Expertise
If you have questions or need assistance with a PFAS-related issue, we can help. We have hands-on experience in the assessment and 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.
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.
Jeffrey Bolin, M.S., reviewed this blog. Jeff is a partner and senior scientist at Dragun Corporation. He is a published author, a frequent speaker, and an expert witness. His expertise in environmental due diligence, PFAS, vapor intrusion, and site assessments has led to projects in the US, Canada, and overseas. See Jeff’s Bio.
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