EPA Designates PFOA & PFOS as Hazardous Substances
EPA Designates PFOS and PFOA as CERCLA Hazardous Substances. What are the Impacts?

On May 8, 2024, the United States Environmental Protection Agency (EPA) published the final designation of two PFAS compounds, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), as “hazardous substances” under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as “Superfund.” The agency warrants this action based on the “totality of the circumstances” and states that the CERCLA listing will be advantageous to cleaning up contaminated sites and facilitating significant public health protection.   

The final PFAS designation comes on the heels of the recent final PFAS MCLs announcement as EPA continues to address key milestones laid out in its PFAS Action Plan and PFAS Strategic Roadmap. Along with the final PFAS MCLs, the CERCLA designation is one of the biggest PFAS headlines this year as it introduces various new operational, liability, and compliance challenges across industries. 

To help the regulated community digest EPA’s action to designate PFOA and PFOS as CERCLA hazardous substances, we dive into important details.  

What are PFOA and PFOS?

PFOA and PFOS are only two of the thousands of PFAS chemicals, but they have attracted a significant share of attention due to their persistence and detection across the globe. PFOA/PFOS were largely phased out of commercial production in the United States (US) in the early 2000s, but remain present in the environment due to widespread historical production and use.

PFOA and PFOS follow textbook acid/base chemistry, and therefore may be present in many forms (e.g., as anions, acids, or salts). Furthermore, either chemical may be present as branched/linear isomers. Also, PFAS precursors that can transform into regulated PFOS and PFOA would need to be considered in a holistic approach. The regulations and analytical methods are designed to apply to PFOA and PFOS regardless of the chemical form. 

What is CERLCA/Superfund?

CERCLA, or Superfund, was enacted in 1980 and provides EPA a funding mechanism and enforcement authority to clean up hazardous waste sites. Through Superfund, EPA can clean up orphan sites or can seek out potentially responsible parties and hold them financially liable for cleanup. 

Superfund is a complex suite of regulations that closely interact with many other environmental regulations. Whether or not a site falls within Superfund’s purview depends on whether it contains CERCLA hazardous substances. Designating PFOA and PFOS as hazardous substances paves the way for Superfund program involvement.   

What are CERCLA Hazardous Substances?

Substances are deemed hazardous if they possess certain toxic, physical, and chemical properties that make them substantially and imminently dangerous to human health and/or the environment upon their uncontrolled release. CERCLA hazardous substances generally rely on designations under other statutes, including the Clean Water Act (CWA), the Clean Air Act (CAA), the Resource Conservation and Recovery Act (RCRA), and the Toxic Substance Control Act (TSCA). However, EPA has the authority to designate substances as hazardous directly under CERCLA Section 102(a), as it did with PFOA and PFOS. No matter which rule makes the declaration, the effects of a hazardous substance designation stretch across the environmental regulatory fabric. 

What Compliance Requirements Does a Hazardous Substance Designation Trigger?

From a practical perspective, once designated as hazardous, substances are added to the Superfund (40CFR) Table 302.4 and require mandatory reporting to the National Response Center after any unplanned environmental releases of each substance above the designated reportable quantity (RQ) of 1 pound (lb) or more over a 24-hour period. In addition to spill rules, hazardous substances are also subject to release tracking, permitting, US Department of Transportation (DOT) manifesting, and reporting under CWA, CAA, RCRA, Toxics Release Inventory (TRI), and/or Hazardous Materials Transportation Action (HMTA). Although PFOA/PFOS are already subject to TSCA Chemical Data Reporting (CDR), phaseouts, and limits, the hazardous designation could trigger additional scrutiny by the EPA. 

According to EPA, the industries potentially affected by this rule include:

Industries Potentially Impacted by EPA’s CERCLA Designation - Chart

When grouped into broad categories, the affected entities may include:

  • Manufacturers and importers

  • Processors 

  • Users

  • Waste management facilities 

  • Wastewater treatment facilities

What is the Intent of EPA’s Action?

EPA’s final designation for PFOA/PFOS intends to: 

  • Increase transparency around releases of PFOA/PFOS

  • Facilitate a federal, state, local, and tribal reporting mechanism of PFOA/PFOS presence/releases into the environment

  • Hold “significant polluters” liable and accountable for cleaning up contamination

  • Enhance community knowledge of the extent and location of PFOA/PFOS and assist in an understanding of how to avoid these chemicals

  • Encourage improved waste treatment and management

  • Expedite contaminated site cleanup

  • Use PFAS cleanup actions to address other co-located contaminants

What About the Environmental and Human Health Basis for the Action?

EPA states that PFOA and PFOS “…may present a substantial danger to human health or welfare or the environment” and that the CERCLA listing of both aims to “…protect people from the health risks posed by exposure to forever chemicals in communities across the country.” EPA elaborates on the potential health risks by stating, “…exposure to PFOA and PFOS may cause adverse health effects, including effects on the immune system, the cardiovascular system, fetus development, and cancer.” However, scientific research is still ongoing to determine how different levels of exposure to different PFAS can lead to various health effects.” Thus, the final PFAS CERCLA listing is precautionary rather than based on a body of existing evidence concerning known US population exposure and adverse effects.  

What are the Potential Impacts on the Regulated Community?

We are in the early stages of the rulemaking activities, so some of the anticipated impacts may change as the proposed rule moves forward. However, certain short- and long-term consequences are likely. 

Along with additional reporting and recordkeeping requirements, the most notable change will be to land/groundwater assessments as part of real estate transactions and valuation. Currently, PFAS are not a compulsory analyte. With the CERCLA listing in place, future land transaction activities will likely need to address PFOA and PFOS in Phase 1 assessments. With this development, EPA is anticipated to resume the suspended rulemaking of the Standards and Practices for All Appropriate Inquiries regulation. Federal property transactions will require covenant warranties on cleanup status, as well as permanent liabilities for any additional remediation actions associated with former storage, release, or disposal of PFOA/PFOS at each site for one year or more.

Another notable impact will be on contaminated site work under CERCLA, RCRA, and state cleanup programs, including the potential for reopening formerly closed sites. The prospect for the latter is amplified by EPA’s parts-per-billion PFAS Maximum Contaminant Limits (MCLs). Waste management under RCRA will also be impacted as PFOA/PFOS testing, transportation manifesting, and disposal will need to follow hazardous material protocols

Additional effects to watch for include:

  • Toxic torts/claims of injury/diminution in value

  • Private party lawsuits for cleanup cost recovery 

  • Pressure to replace PFOA/PFOS industrial chemistries/processes domestically and in imported goods with non-hazardous alternatives

  • Further public water supply challenges where PFOA/PFOS are detected

  • The listing of new sites on EPA’s National Priorities List (NPL)

  • The potential for EPA to exercise its authority to order private parties to repay cleanup costs or perform cleanup themselves 

  • Increased frequency of site investigation and environmental risk assessments for PFOA/PFOS

  • The potential for EPA to name additional PFAS compounds currently under risk assessment or part of other regulations as hazardous substances       

Anything Else I Should Know?

EPA states that they will use enforcement discretion policy and other approaches to ensure fairness to parties that were inadvertently impacted by the contamination. However, details are lacking on how the agency will make its determination as to which party is identified as the “significant polluter” subject to cleanup cost recovery under the rule for addressing “significant contamination.” Though, the rule language has provisions for minor sources, third parties, small municipal waste generators, perspective purchasers, innocent landowners, off-site properties, permitted emitters, and fertilizer (but not explicitly biosolids) applicators on limiting liabilities and financial impacts. Notably, the public potable water treatment sector is not mentioned in the rule “exempt” category, yet thousands of small and large water providers may be affected even if PFAS are detected below the final MCLs. Instead, EPA’s approach appears to be policy-based for case-specific enforcement actions and deems this sector already settled under the recent final PFAS MCL rule

What’s Next? 

The rule becomes effective on July 8, 2024. The EPA has also indicated that it expects to issue an Advance Notice of Proposed Rulemaking in the future to solicit public comment on designating additional PFAS as CERCLA hazardous substances. 

How to Prepare Now

Designating PFOA/PFOS as CERCLA hazardous substances will create an influx of CERCLA sites across industries and could impact sites that have received Records of Decision (RODs) or No Further Action (NFA) letters. While the impacts of the proposed rule may be considerable, there are ways site owners and operators can begin preparing for regulatory changes, including:

  • Examine current chemical inventories for any PFAS

  • Scrutinize safety data sheets (SDS) for PFAS-containing chemicals/products

  • Look for substitutions/alternate processes

  • Implement/extend hazardous substances management programs (if elimination/substitution is not possible)

  • Understand reporting requirements

  • Create facility-specific conceptual site models (CSMs) to understand on-site/off-site contributions

  • Examine past site uses and activities that may have led to PFAS releases

  • Understand facility’s public information footprint

If you have questions on how EPA’s final PFOA/PFOS CERCLA listing will impact you, please connect with us using the form linked below.


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Andrew Pawlisz Headshot
Andrew Pawlisz, DABT
Regulatory Toxicologist, Owasso, OK

Andrew is a board-certified toxicologist with over 21 years of experience in risk assessment and evaluation; hazard assessment; and regulatory compliance, including the legacy and reformed Toxic Substances Control Act (TSCA). Andrew specializes in finding practical solutions to regulatory and human health/environmental issues related to toxicants.

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