Per- and polyfluoroalkyl substances (PFAS) represent a large group of synthetic chemicals that have been in use since the 1940s in a wide variety of consumer and industrial products. While PFAS can take different forms, their common characteristic is the presence of multiple fluorine atoms. The carbon–fluorine bond is the strongest chemical bond in organic chemistry.

Due to the strength of the carbon–fluorine bond, the PFAS molecules are chemically very stable and are highly resistant to biological degradation. As a result, they persist in the environment. PFAS also repel both water and oil, giving them excellent surfactant capabilities. The chemicals are relatively mobile and can travel quickly through surface and groundwater, too.

With PFAS detections in drinking water supplies becoming more frequent, federal and state agencies are increasingly vocal in responding to public concern over PFAS contamination. There is some risk that these agencies may act before the data are fully in.

Scientific Basis

It is still unclear exactly how PFAS affect human health. As admitted by David Ross, U.S. EPA Assistant Administrator for Water, during a March 28 congressional hearing on PFAS, “the body of science necessary to fully understand and regulate these chemicals is not yet as robust as it needs to be.” And the National Center for Environmental Health continues to report on its website that “[s]tudies in humans and animals are inconsistent and inconclusive but suggest that certain PFAS may affect a variety of possible endpoints. Confirmatory research is needed.”

Until the scientific studies are able to provide more consistent information about the extent and manner in which PFAS cause harm, federal and state agencies should take caution in adopting onerous regulatory requirements that provide uncertain health benefits.

Drinking Water

Under the Safe Drinking Water Act (SDWA), the EPA has the authority to set enforceable maximum contaminant levels (MCLs) for specific chemicals and can require monitoring of public water supplies. There are currently no MCLs established for PFAS chemicals, but the EPA has announced that it will evaluate the need for an MCL for two PFAS compounds under the regulatory determination process. In order to adopt an MCL under the SDWA, the EPA must publish a determination that the benefits of the standard justify the inherent costs of imposing additional testing and treatment requirements on thousands of water systems across the country.

Any actual movement toward setting an MCL for PFAS compounds will generate a massive response from federal agencies—among them, the Defense Department, which uses firefighting foams containing PFAS in training exercises at military bases, which are one source of groundwater contamination. These agencies would become liable for considerable cleanup requirements if a low MCL is set.

Sen. Tom Carper (D-Del.) has already complained to the EPA of reported actions by several federal agencies to thwart the EPA’s proposed—and in their opinions, too burdensome—groundwater cleanup standards. While reports of “behind the scenes” discussions may be titillating for the media, these agencies are simply raising the undeniable point that the EPA will have to provide technical justification for any regulatory limit that is set. Any justification will necessarily need to take into account the limited and conflicting scientific data available on PFAS.


As part of its recent action plan, the EPA also stated that it is moving forward with designating two PFAS compounds—perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)—as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the Superfund law. This listing could have significant ramifications given the scope of relief CERCLA provides.

Under CERCLA, plaintiffs can recover response costs incurred by contamination from a listed substance. These listed substances include chemicals designated as hazardous substances under either federal or state law. The EPA and private parties can already bring CERCLA suits for PFAS contamination in states where state laws or regulations have designated certain PFAS compounds as hazardous substances. But to date, that is only a small number of states.

Designating PFOA and PFOS as federally listed hazardous substances will dramatically increase the number of sites where CERCLA actions would be available.

Technical Note

The persistence of PFAS compounds and the large number of chemical variations (and precursors) makes the testing and treatment of PFAS technically complicated. And given the prevalence of PFAS in so many ordinary consumer products, testing of PFAS compounds is highly susceptible to cross-contamination, resulting in false positives.

Despite the scientific uncertainty over health impacts from PFAS exposure, agencies have continued to push for further investigation and testing for PFAS in consumer products, industrial and manufacturing sites, and public water systems. Companies and public entities that have received administrative orders should take care to ensure that testing and treatment is done correctly and without unnecessary legal risk.

All told, private enterprise and federal agencies alike should ensure that the EPA and other agencies comply with their obligations to the public to ensure that the costs imposed by further regulation are justified by the corresponding—and sufficiently established—benefits to the public health.

This column does not necessarily reflect the opinion of The Bureau of National Affairs Inc. or its owners.

Author Information

Meaghan Boyd is a partner in Alston & Bird’s Environment, Land Use and Natural Resources Group, where she defends companies in complex environmental and toxic tort litigation in federal and state courts. Matthew Wickersham, counsel at Alston & Bird, focuses on environmental regulation and litigation on behalf oil & gas, manufacturing, and defense companies.

*Original article online at