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Regulatory Updates

EPA Issues Proposed Rule Designating PFOA and PFOS as Hazardous Substances

Elizabeth Denly & Catriona Smith | September 7, 2022

The Environmental Protection Agency (EPA) has issued the proposed rule to designate two PFAS compounds as hazardous substances under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). The EPA is proposing to designate perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), including their salts and structural isomers, as hazardous substances.

The proposed rule states that it is intended “to promulgate regulations designating as hazardous substances such 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. Such a designation would ultimately facilitate cleanup of contaminated sites and reduce human exposure to these “forever” chemicals”. Comments must be received on or before 60 days past the date of publication (September 6, 2022) in the Federal Register, which would be until November 7, 2022.

The main take-aways from this proposed rule are:

  • The proposed rule sets a reporting quantity (RQ) of 1 pound or more in a 24-hour period. Any release above the 1-pound RQ of PFOA or PFOS (and their salts and structural isomers) would have to be reported to EPA.
  • CERCLA casts a wide net – this rule potentially expands the universe of sites and facilities subject to CERCLA cleanup of PFOA and PFOS to those with no direct history of manufacture or use, due to the ubiquitous nature of these compounds, and may allow “re-openers” of “closed” or “no further action” sites, including (former) brownfields redevelopment sites, in addition to potentially adding requirements for active CERCLA sites.
  • A designation as a CERCLA hazardous substance could make the path toward a RCRA hazardous waste listing much easier.

What you can do now:

  • Talk to your State and Local Representatives to express your opinions on the proposed rule.
  • Provide comments on the proposed rule.
  • Proactively address your potential risk associated with PFAS compounds by contacting a TRC expert.


  • EPA Pre-Publication Notice & Proposed Rule
  • Comments can be submitted
    • Via the Federal eRulemaking Portal: (preferred method). Follow the online instructions for submitting comments, and include the Docket ID No. EPA-HQ-OLEM-2019-0341; or
    • Via mail to:  U.S. Environmental Protection Agency, EPA Docket Center, OLEM Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460; or
    • Hand delivered/courier to: EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
Elizabeth Denly

Elizabeth Denly serves as TRC’s Vice President, PFAS Initiative Leader. She is also the Quality Assurance & Chemistry Director, responsible for the creation and implementation of the Quality Management Plan and standard operating procedures (SOPs) for field sampling and documentation protocols. Ms. Denly also leads Quality Coordinator networks, which are responsible for the development and communication of quality initiatives within the organization. She is a chemist with 29 years of consulting experience encompassing field and laboratory analyses and audits, QA/QC, data validation, and consulting for regulatory agencies.

Ms. Denly is a leader in ITRC’s PFAS and TPH Risk Work Groups and in TRC’s Center of Research & Expertise (CORE) Emerging Contaminants Team and received the ITRC’s Industry Member of the Year Award in 2017. She is currently focusing on PFAS, specifically the nomenclature, chemistry, sampling procedures, QA/QC, and laboratory analytical methodologies, and has a significant role in educating clients, attorneys, and regulators about PFAS.

As a senior QA specialist at TRC, Ms. Denly is responsible for providing QA/QC oversight in support of a variety of environmental investigations and remediation programs including risk-based soil cleanups, ambient air monitoring, and human health and ecological risk assessments. In this role, she has directed the preparation of QAPPs, coordination with the laboratory, selection of the appropriate analytical methodologies to achieve the desired remedial standards, oversight and performance of the data validation process, and determination of the usability of the data and achievement of data objectives. Ms. Denly has provided this oversight under different regulatory programs.
Read more on Ms. Denly’s bio page. Please contact her at

Catriona Smith

Catriona (Cat) Smith has over 30 years of professional experience in the interpretation and application of regulations for industrial facilities relating to compliance, remediation and negotiations with regulatory agencies. Her clients include upstream and downstream oil and gas, chem-pharma, petrochem, manufacturing and federal, state, and local governments. Ms. Smith is a Vice President and Environmental Sector Market Director for TRC, with nationwide responsibilities to manage our clients’ PFAS challenges, support and grow our Oil and Gas clients and bring multi-disciplinary solutions to their complex projects. Contact Cat at

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