The EPA Releases New PFAS Health Advisories

Posted on behalf of Alana Acuna and Heather Lynch

On June 15, 2022, the US Environmental Protection Agency (EPA) released new lifetime Health Advisories (HAs) for four per- and polyfluoroalkyl substances (PFAS) in drinking water (EPA, 2022). The EPA’s HAs serve as technical values for guiding officials and water system managers in protecting public health, and are non-regulatory and non-enforceable. The new HAs are 0.004 ppt for perfluorooctanoic acid (PFOA), 0.02 ppt for perfluorooctane sulfonic acid (PFOS), 10 ppt for hexafluoropropylene oxide dimer acid (“GenX chemicals”), and 2,000 ppt for perfluorobutane sulfonic acid (PFBS). The HAs for GenX chemicals and PFBS are final, while the PFOA and PFOS HAs are interim. However, the EPA recently indicated that the final HAs for PFOA and PFOS may be higher than these initial values (Bloomberg, 2022).

Perhaps most striking, though, is the associated White House briefing on PFAS, which states that “… some negative health effects may occur with concentrations of PFOA and PFOS in water that are near zero”, implying that no safe exposure level exists (White House, 2022). As noted by other sources, the PFOA and PFOS values are well below many state drinking water values, and, perhaps more importantly, below levels at which these PFAS can be reliably measured.

Further, the interim PFOA and PFOS HAs represent 17,500-fold and 3,500-fold reductions, respectively, over the previous 70 pt HAs (individual and combined). The 2016 PFOA and PFOS HAs were both based on developmental effects in highly exposed rodents. The current HAs are based on decreases in antibody levels after routine childhood vaccination, as measured in children living in the Faroe Islands. Notably, in 2016, the EPA reviewed one of the critical HA studies (Grandjean et al. 2012). The EPA, however, appeared less certain of possible immune health hazards in humans at that time. In the 2016 PFOA HA, for example, the EPA states, “Taken together, available human studies do not provide consistent evidence of a significant association between PFOA exposure and serological vaccine responses in general” (Grandjean et al. 2012; Granum et al. 2013; Looker et al. 2014). The more recent critical study used in the 2022 HA is a benchmark dose analysis of the previously analyzed Faroe Island cohorts (i.e., a reanalysis of the same cohort) (Budtz-Jorgensen, 2018).

These new releases mark the  first time that EPA HAs have been released for any PFAS other than PFOA and PFOS. North Carolina and Michigan developed the only other guidance levels for GenX and related chemicals in drinking water, indicating 140 and 370 ppt, respectively (NCDHHS, 2021; Michigan, 2021). North Carolina, however, has been discussing possibly adopting the new EPA HA. On the other hand, state PFBS levels vary widely, with some much higher and some slightly lower than the final EPA HA. Michigan, for example, set a maximum containment level (MCL) of 420 ppt, but Illinois and Minnesota set MCLs of 140,000 and 100,000 ppt, respectively (Michigan, 2021; Illinois EPA, 2021; MDH, 2022).

These HAs represent the first steps on the EPA’s path toward issuing enforceable drinking water standards for some PFAS. By the end of this year, the EPA plans to propose a PFAS National Drinking Water Regulation for PFOA and PFOS. In addition, the EPA is currently evaluating five more PFAS: perfluorobutanoic acid (PFBA);, perfluorodecanoic acid (PFDA); perfluorohexanoic acid (PFHxA); and perfluorohexyl sulfonate (PFHxS), and plans to issue Has once the evaluations are complete.

Cardno ChemRisk now Stantec scientists have decades of experience understanding perfluoroalkyl substances (PFAS) hazard and exposure. Please visit Cardno ChemRisk now Stantec’s PFAS page for more information regarding our capabilities. If you would like to learn more about our capabilities, or have any further questions regarding these topics, please contact Heather Lynch.