EPA’s New Drinking Water Health Advisories for PFAS Chemicals

We previously blogged on this topic here and here.

Under the Safe Drinking Water Act, EPA may publish health advisories for contaminants that are not subject to any national primary drinking water regulation. These health advisories are intended to provide technical information that federal, state, and local agencies can use to inform actions to address PFAS in drinking water, including water quality monitoring, optimization of existing technologies that reduce PFAS, and strategies to reduce exposure to these substances. 

The new advisories apply to four PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), final health advisories for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (together referred to as “GenX chemicals”), and perfluororbutane sulfonic acid and its related compound potassium perfluororbutane sulfonate (together referred to as “PFBS”). The advisories for PFOA and PFOS are “interim” in that they are meant to be in place until EPA’s issuance of a National Primary Drinking Water Regulation for PFAS. A proposed version of that regulation is expected later this year.  They are therefore not yet enforceable by law.  The advisories for GenX and PFBS, however, are final.

The health advisories, which identify the concentration of chemicals in drinking water at or below the level at which adverse health effects are not anticipated to occur, are:

• 0.004 parts per trillion (ppt) for PFOA;
• 0.02 ppt for PFOS;
• 10 ppt for GenX chemicals; and
• 2,000 ppt for PFBS

Among other stakeholders, the American Chemistry Council responded to the new interim advisories by pointing out that these levels are below current reliable testing and treatment capabilities and that the underlying supporting reports are subject to ongoing review by EPA’s Science Advisory Board.

Prior PFAS Heath Advisories

The interim health advisories replace EPA 2016 final health advisories for PFOA and PFOS, which were both set at 70 ppt. As noted by the American Chemistry Council, the studies underlying the new advisories are currently undergoing EPA Science Advisory Board review. EPA has explained that it is proceeding with the new advisories regardless due to its concern about the public health implications of its preliminary findings regarding these chemicals.

GenX Chemicals and PFBS

This is the first time EPA has issued health advisories for these chemicals. (GenX chemicals are often considered as replacements for PFOA, and PFBS is often considered a replacement for PFOS.)

Next Steps

EPA plans on proposing a PFAS National Drinking Water Regulation this fall.  These advisories, as they relate to PFOA and PFOA, are intended to provide guidance for the period prior to that regulation going into effect.