The Agency for Toxic Substances and Disease Registry (ATSDR), a subset agency within the Centers of Disease Control and Prevention (CDC), published an update on the toxicological profile for 10 specific PFAS chemicals on May 5.

The Report provides the most current peer-reviewed toxicological studies on the health effects, toxicokinetics, chemical and physical information, and potential for human exposure along with the adequacy of the database. This update builds upon a prior ATSDR toxicological profile for PFAS published in March of last year.

Unlike EPA’s methodology for developing drinking water health advisories (HAs) under the Safe Drinking Water Act, ATSDR develops minimal risk levels (MRLs) as a screening tool to identify chemicals of concern. These MRLs consider different data and factors than EPA’s lifetime HAs and are used by ATSDR to determine areas and populations that are potentially at risk for health effects from exposure to a particular substance. Exposure above an MRL does not mean health problems will happen nor carry any regulatory implication or necessary compliance action. The updated toxicological profiles preserve the MRLs proposed by ATSDR in early 2018 and in 2020 reports.

EPA has established a lifetime HA level of 70 parts per trillion (ppt) for PFOA and PFOS, two of the more common PFAS constituents. Because ATSDR and EPA’s approaches rely on different data and different factors, it is unlikely that EPA will revise the lifetime HA level of 70 ppt. The Agency may however refer to ATSDR’s report as it moves through its regulatory determination processes for assessing whether or not to establish a national primary drinking water regulation for PFOS and PFOA.

If members have questions, please contact Emily Remmel, NACWA’s Director of Regulatory Affairs.