EPA has published a notice of proposed rulemaking, Addressing PFAS in the Environment, asking for public input, which the Agency will use to develop future per- and polyfluoroalkyl substance (PFAS) regulations under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Agency asked for information on the potential future hazardous substance designation of a number of PFAS, categories of PFAS, and several PFAS precursors.
Request for Public Input Regarding Potential Future Hazardous Substance Designation of Seven PFAS
EPA had previously proposed designating PFOA and PFOS and their salts and structural isomers as hazardous substances under CERLA. The present notice requested feedback as to whether the agency should initiate action designating an additional seven PFAS and their salts and structural isomers or a subset thereof as CERCLA hazardous substances as well. The seven PFAS being considered for designation are:
- Perfluorobutanesulfonic acid (PFBS), CASRN 375–73–5
- Perfluorohexanesulfonic acid (PFHxS), CASRN 355–46–4
- Perfluorononanoic acid (PFNA), CASRN 375–95–1
- Hexafluoropropylene oxide dimer acid (HFPO–DA), CASRN 13252–13–6
- Perfluorobutanoic acid (PFBA) CASRN 375–22–4
- Perfluorohexanoic acid (PFHxA) CASRN 307–24–4
- Perfluorodecanoic acid (PFDA) CASRN 335–76–2
EPA asked interested parties to submit information on whether any of these compounds may present substantial danger to public health or welfare or the environment. Such information could include data on mobility, persistence, and prevalence.
Request for Public Input Regarding Potential Future Hazardous Substance Designation of Precursors to PFOA, PFOS, and PFAS
The Agency is also considering initiating action that would designate certain PFAS precursors as hazardous substances under CERCLA. To make this determination, EPA requested information to help the Agency identify compounds that degrade to these PFAS through environmental processes such as biodegradation and hydrolysis.
Request for Public Input Regarding Potential Designation, or Designations, of Categories of PFAS as Hazardous Substances
Additionally, EPA is considering initiating action that would designate groups or categories of PFAS as CERCLA hazardous substances. These groups or categories would be based on characteristics that determine risk to human health and the environment, such as chemical structure, physical and chemical properties, mode of toxicological action, and precursors or degradants. To inform its decision-making, the Agency solicited the following information:
- Published scientific literature that can inform whether categories of PFAS could or could not be designated as hazardous substances. This could include findings on the similarities or differences of a specific characteristic among PFAS. Also useful would be data on the relationship between different characteristics, such as the relationship between chemical structure and specific chemical, physical, or toxicological properties.
- Other information that could inform EPA’s determination of whether to designate one or more categories of PFAS as hazardous substances.
- Information that would contribute to economic analysis of the potential costs and benefits, including impacts on small entities, associated with a potential rulemaking designating categories of PFAS as hazardous substances. (Although CERCLA section 102(a) precludes EPA from taking cost into account in the designation of a hazardous substance, the Agency is requesting this information to help the Agency understand the potential costs and benefits associated with any potential future regulatory action.)
The deadline for submitting comments was extended from June 12 to August 11, 2023, during which period over 600 comments were submitted. The comments can be reviewed here.