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Persistent Pollutants

EPA targets 6 PFAS in drinking water

US proposal sets limits for legacy and commercially relevant ‘forever’ chemicals

by Britt E. Erickson
March 14, 2023


The US Environmental Protection Agency is forging ahead with a plan to regulate per- and polyfluoroalkyl substances (PFAS) in drinking water. In a proposal announced March 14, the agency sets legally enforceable limits on 6 of the more than 10,000 chemicals in this class of so-called “forever” chemicals, known for their grease- and water-resistance properties and their slow degradation.

Chemical structure of PFOA.
Chemical structure of PFOS.

Two of the six targeted PFAS—perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—are toxic at extremely low levels. The EPA proposes to set a drinking water limit for those two chemicals at 4 parts per trillion (ppt) each. The agency wants to regulate the other four PFAS—perfluorobutane sulfonic acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and hexafluoropropylene oxide dimer acid (HFPO-DA, used in Chemours’ GenX product)—as a mixture using an approach that determines the combined risk of the chemicals.

If the proposal is finalized, public water systems will have to monitor for the six chemicals in drinking water and keep levels below the regulatory limits. They will also have to alert the public when levels exceed the limits.

PFOS and PFOA are no longer produced in the US, primarily because of their toxicity. The compounds have been linked to cancer, liver damage, and high cholesterol. But they were used for decades in products such as nonstick frying pans, cosmetics, and stain-resistant fabrics. Concerns have also been raised about the health effects of some of their replacements, such as GenX.

“These toxic chemicals are so pervasive and so long-lasting in the environment that they’ve been found in food, soil, and water even in the most remote corners of our planet,” EPA administrator Michael Regan said during a press conference announcing the drinking water standards. Regan made the announcement from Wilmington, North Carolina, where regulators and community activists have been fighting since 2017 to clean up drinking water contaminated with GenX chemicals from a nearby Chemours facility. Chemours was spun off from DuPont in 2015. “We anticipate that when fully implemented, this rule will prevent thousands of deaths and reduce tens of thousands of serious PFAS-related illnesses,” Regan noted.

These low limits will likely result in billions of dollars in compliance costs.
American Chemistry Council

The EPA’s action comes after months of delay and a lawsuit from the chemical industry over the agency’s health advisories for PFOA and PFOS, which were released in June 2022. Those advisories recommended drinking water limits of 0.004 ppt for PFOA and 0.02 ppt for PFOS. The EPA’s previous recommended limits, set in 2016, were 70 ppt for each.

But such health advisories are not enforceable. A federal court recently threw out a lawsuit from the American Chemistry Council (ACC) that challenged the EPA’s updated advisories. A three-judge panel ruled that the chemical industry group failed to show that its member companies were harmed by the non-enforceable advisory limits.

In a statement about the EPA’s latest proposed limits, which are enforceable, the ACC says it has “serious concerns with the underlying science.” The group calls the EPA’s approach to developing the drinking water limits “misguided,” adding that “these low limits will likely result in billions of dollars in compliance costs.”

Environmental and community groups welcome the EPA’s decision to crack down on PFAS contamination in drinking water, which is widespread throughout the US. “We applaud the Biden EPA for having the courage to do what multiple administrations could not. Today is a good step towards tackling our nation’s massive PFAS public health crisis by including commercially relevant PFAS like GenX,” Emily Donovan, cofounder of Clean Cape Fear, a community group in North Carolina working to hold Chemours and DuPont accountable for pollution, says in a statement.


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