Earlier this month, EPA set new lifetime health advisories for four per- and poly-fluoroalkyl substances (PFAS) – in some instances at levels lower than those that can be detected through laboratory testing. The new health advisories are listed below:
|PFAS||Health Advisory (in parts per trillion)|
|PFOA (perflurooctanoic acid)||0.004 ppt|
|PFOS (perfluorooctane sulfonic acid)||0.02 ppt|
|GenX (hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt)||10 ppt|
|PFBS (perfluorobutane sulfonic acid and its potassium salt)||2,000 ppt|
EPA’s previous health advisories for PFOA and PFOS were 70 ppt (individually or combined), so these new, interim advisories are significantly lower. The advisories for GenX and PFBS are completely new. And all are getting attention.
The health advisories are not enforceable standards; however, in EPA’s own words, they “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.” Indeed, some states adopted drinking water regulations based on EPA’s now outdated 70 ppt health advisory for PFOA and PFOS.
According to EPA, it reviewed over 400 human epidemiological and animal toxicity studies in determining the health advisories for PFOA and PFOS. GenX and PFBS have not been as extensively studied to date, and those advisories appear to be based only on animal toxicity studies. EPA acknowledged that, for PFOA and PFOS, the levels are set at “near zero” and “below EPA’s ability to detect at this time.” However, it claims that new science and a consideration of lifetime exposure (including PFAS exposure from sources other than drinking water) support “aggressive” action.
EPA plans to develop a proposed National Drinking Water Regulation for PFOA and PFOS by the end of 2022. This proposed regulation will include a Maximum Contaminant Level (MCL), which is almost certain to be well above the health advisories EPA just established for these compounds. If adopted, the MCL for PFOA and PFOS would become an enforceable standard for drinking water. EPA also indicated that it is considering actions to address other PFAS, or groups of PFAS, beyond PFOA and PFOS.