The EPA has proposed designating two “forever chemicals” as hazardous substances under the Superfund law.

The proposal released Friday would designate the two most widely used per- and polyfluoroalkyl substances — perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) — under the Comprehensive Environmental, Compensation and Liability Act. If finalized, it would require releases of one pound or more within a 24-hour period to be reported, which the agency said would provide it with better data as well as the option to require cleanups and recover costs.

“Under this proposed rule, EPA will both help protect communities from PFAS pollution and seek to hold polluters accountable for their actions,” said EPA Administrator Michael S. Regan, using the commonly used abbreviation for the group of chemicals.

The EPA said it will publish the rule in the coming weeks, which will trigger a 60-day public comment period. The agency also anticipates issuing a separate notice after the close of the comment period seeking comment on the possibility of designating other PFAS chemicals as hazardous substances.

PFAS have been used in a wide array of commercial applications, ranging from firefighting foam to nonstick cookware. They have been called forever chemicals because they break down slowly and persist in both the human body and the environment. Exposure is linked to certain types of cancer and other health problems such as low birth weight and endocrine system disruption.

After the Trump administration was criticized for failing to act on PFAS the Biden administration promised to finalize federal regulations. In June the EPA issued updated drinking water health advisories for PFOA and PFOS that are drastically lower than those set in 2016 and below detection levels that the agency determines can be reliably measured in water using approved testing methods in a laboratory setting.

The EPA said it expects to propose national drinking water regulations for PFOA and PFOS by the end of the year, with a final rule expected in 2023.

“Too many communities across the country are struggling to address the presence of PFAS chemicals on their land and in their waters. Hats off to EPA for taking this bold and necessary step to get those responsible for this contamination to pitch in and help communities to clean up,” Senate Environment and Public Works Chairman Thomas R. Carper, D-Del., said in a statement.

The committee’s ranking member Sen. Shelley Moore Capito, R-W.Va., also supports action on PFAS and after the announcement reiterated her support for an enforceable drinking water standard. However, she expressed concern about the “uncertainty and unintended consequences that today’s proposal could have.”

“If this proposal is finalized, property owners, farmers, employers, essential utilities, and individuals may be liable for unknowingly having PFAS on their land, even if it was there years or even generations prior to ownership and came from an unknown source,” said Capito.

Water and wastewater utilities have expressed similar concerns that a Superfund designation may shoulder them with costs for chemicals they themselves did not create. The agency said during consideration of the proposed rule it will conduct outreach with impacted communities, wastewater utilities, businesses and farmers.