Tom Carper, U.S. Senator from Delaware; image from United States Senate, Public domain, via Wikimedia Commons
Tom Carper, U.S. Senator from Delaware; image from United States Senate, Public domain, via Wikimedia Commons

U.S. Senate Committee Proposes Bill That Excludes F-Gases and TFA from Definition of PFAS

Stakeholders can provide feedback on the bill through July 3.

U.S. Senators Tom Carper (Democrat from Delaware) and Shelley Moore Capito (Republican from West Virginia) – Chair and Ranking Member, respectively, of the Senate Environment and Public Works (EPW) Committee – on June 22 released draft PFAS (per- and polyfluoroalkyl substances) legislation that, among other measures, narrowly defines PFAS in a way that excludes f-gases and trifluoroacetic acid (TFA), the atmospheric byproduct of certain f-gases.

Many f-gases and TFA are regarded as ultra-short-chain PFAS under a broader definition widely accepted in the scientific community and used throughout the world.

The EPW Committee is seeking stakeholder comments on the draft legislation by Monday, July 3, 2023. Comments can be submitted here. A section-by-section summary of the bill can be found here.

PFAS covers a wide range of chemical compounds, reportedly ranging from 6,500 under a narrow definition to more than 10,000 under a broader one.

According to the draft bill, PFAS would be defined as “a non-polymeric perfluoroalkyl or polyfluoroalkyl substance; and a side chain fluorinated polymer that is a member of a group of human made chemicals that contain at least 2 fully fluorinated carbon atoms.”

In a statement from the EPW Committee, this definition was described as providing “a consistent and practical definition of PFAS compounds for use by federal agencies, state governments, and other entities.”

However, a number of U.S. states, including Maine and California, as well as the EU, have adopted a broader definition of PFAS that includes f-gases and TFA. This definition, published in 2021 by the OECD (Organization for Economic Co-operation and Development) and endorsed by a wide range of scientists, defines PFAS as fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom.

The OECD definition of PFAS not only includes f-gases but the TFA into which some f-gases, notably HFO-1234yf, decompose in the atmosphere. TFA comes down to Earth in rainwater and has been found to accumulate in water supplies and arctic ice, raising concerns about its ultimate health impact.

The proposed EPW bill is also at odds with legislation introduced in 2021 by Representatives Deborah Ross (Democrat from North Carolina) and Nancy Mace (Republican from South Carolina) called the PFAS Definition Improvement Act (HR 5987), which defined PFAS as the OECD does.

EPA drops ‘working definition’ of PFAS

Up until recently, the U.S. Environmental Protection Agency (EPA) had already been employing the more restrictive definition of PFAS ­– what it calls the “working definition” in its National PFAS Testing Strategy –that is indicated in the EPW bill. However, under criticism by scientists and a number of NGOs, the EPA’s Office of Pollution Prevention and Toxics (OPPT) stated in a May 23 email that it “is no longer using a ‘working definition’ to characterize the universe of PFAS subject to the office’s various PFAS testing, reporting and regulatory efforts. Moving forward, OPPT intends to continue to explain the rationale for identifying specific PFAS substances it believes are appropriate to include within the scope of each individual action.”

This email was shared by Tim Whitehouse, Executive Director, Public Employees for Environmental Responsibility (PEER), in a presentation at the ATMOsphere (ATMO) America 2023 conference, held in Washington, D.C., June 12–13. ATMO America was organized by ATMOsphere, publisher of

In April 2022, in a suit against the EPA, PEER alleged that the agency was “withholding documents explaining why it has adopted an exceedingly limited definition of [PFAS].”

EPA subsequently released more than 2,500 pages of documents, but in June 2022 PEER said in a statement that it found “no scientific basis” for the EPA’s working definition of PFAS, and “no reasons given for excluding thousands of chemicals included in State definitions.” PEER added that it would challenge in court redactions in the EPA’s documents that “may mask the scientific basis” for its PFAS definition. Whitehouse said at ATMOsphere America 2023 that PEER’s suit against the EPA is ongoing.

The EPA has also refrained from treating PFAS as a class of chemicals, preferring to approach them one chemical at a time. Robert Sussman, Principal of Sussman and Associates, and a former Deputy Administrator at the EPA, urged that PFAS be treated as a class at the ATMO America 2023 conference and pointed to the broader definition of PFAS used by the EU. “Restricting PFAS one chemical at a time would not prevent ongoing pollution and continuing build-up in people and the environment,” he said.

While the health effects of TFA are not yet fully understood, PFAS scientist Heidi Pickard, a PhD Candidate at Harvard University, said at ATMO America 2023 that the fact that chemicals like TFA are “very persistent and very mobile, and will accumulate in aquatic ecosystems, are bioavailable and bioaccumulative – that alone warrants concern about these chemicals that needs further evaluation and study.”

In the EU, the European Chemicals Agency (ECHA) In February published a proposal from the national authorities of Denmark, Germany, the Netherlands, Norway and Sweden to restrict PFAS under REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the EU’s chemicals regulation, following the OECD definition of PFAS. The “Universal Restriction Proposal” – officially known as the Annex XV Restriction Report – would restrict the manufacture, use or sale of certain f-gas refrigerants as substances on their own or in blends according to certain thresholds.

ATMOsphere has joined forces with the International Chemical Secretariat (ChemSec) to explain to interested companies operating with natural refrigerants how to submit relevant data to the ongoing ECHA consideration of the PFAS proposal. The workshop will be held online on June 28 from 11 to 12 CEST. Registration to the webinar is available at this link. ATMOsphere reserves the right to grant access to the webinar.

Other provisions of proposed bill

The EPW Committee, in its statement on the proposed PFAS bill, noted that the EPA is “already working to finalize drinking water standards, hazardous substance designations, and risk assessments for PFAS through the agency’s various regulatory processes—among other federal actions to respond to PFAS contamination.”

To that end, the draft legislation includes provisions that:

  • Set a September 30, 2024 deadline for EPA to complete the agency’s ongoing rulemaking process to set drinking water standards for specific PFAS substances;
  • Support the ability of states to inventory industrial users of PFAS within their borders;
  • Authorize grant programs for the development of treatment technologies for PFAS; and,
  • Create a prize competition to encourage innovation in the development of technologies that can help identify PFAS in the environment, prevent further contamination, and remediate or destroy PFAS.

The EPW Committee also noted that theEPA “has gaps in its knowledge and available scientific information about this large class of substances.” To fill these gaps and “build public support to address growing public concerns” the draft bill includes provisions that:

  • Help bolster our understanding of beneficial and nonessential uses of PFAS in commerce;
  • Direct EPA to create a clearinghouse of state and private sector best practices to support informed decision-making on these chemicals; and,
  • Direct EPA to work with an external standards-setting organization to supplement the agency’s work on PFAS standards—including for detection, reduction, destruction, remediation, and verification.

In addition, given thatthe contamination from PFAS is widespread, the draft legislation includes provisions that:

  • Amend the Safe Drinking Water Act State Response to Contaminants program, as amended in the Infrastructure Investment and Jobs Act, to allow states to assist individual well owners; and,
  • Authorize a new emergency response program to support our most vulnerable communities plagued by acute contamination issues.]

Chemicals like TFA are “very persistent and very mobile, and will accumulate in aquatic ecosystems, are bioavailable and bioaccumulative – that alone warrants concern about these chemicals that needs further evaluation and study.”

Heidi Pickard, PhD Candidate, Harvard University

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