The latest action from the Environmental Protection Agency (EPA) on the regulation of per- and poly-fluoroalkyl substances (PFAS) includes an update to drinking water health advisories for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) along with new drinking water health advisories for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (GenX) and perfluorobutane sulfonic acid and its potassium salt (PFBS). The health impacts of PFOA and PFOS were addressed in prior health advisories released by EPA in 2016 that established lifetime exposure levels in drinking water at 70 parts per trillion. EPA also established new health advisories for the two replacement chemicals for PFOA and PFOS, GenX and PFBS, respectively. The table below outlines the new health advisory levels.
While EPA health advisories are not enforceable, they are often used by state regulators and federal agencies as standards for environmental programs. For example, many states adopted the previous health advisory levels for PFOA or PFOS as their drinking water standard. Health advisories can also be used as cleanup standards under other environmental laws. EPA will soon release a maximum containment level under the Safe Drinking Water Act for PFOA and PFOS. The maximum contaminant level (MCL) that EPA will establish for PFOA and PFOS will most likely be significantly higher than the Health Advisory level because of Safe Drinking Water Act (SDWA) requirements for establishing MCLs. Any variation in the MCL from the Health Advisory for PFOA and PFOS is going to pose a significant communication issue for water utilities and state regulators as they try to explain that the finished product is safe for consumption despite being significantly higher than the Health Advisory.
While the disparity between the health advisory and the final MCL will be an issue for states and water utilities, one sentence in EPA’s press release announcing the Health Advisory is going to garner significant attention. In the release EPA notes that, “… the agency is also evaluating additional PFAS beyond PFOA and PFOS and considering actions to address groups of PFAS [emphasis added].” If this is a reference to the National Testing Strategy designed to categorize groups of PFAS for prioritization under section 4 of TSCA, then it merely restates how EPA is managing its workload regarding PFAS. However, if this means that EPA is going to perform analysis of PFAS chemicals as a class for purposes of regulation, that would be a significant departure from past practice. As demonstrated by the Health Advisories released on June 15, 2022, all PFAS chemicals are not the same and grouping them together when developing Health Advisories or taking other regulatory actions will be controversial.
While EPA’s announcement of two new health advisories and two revised health advisories will garner the most attention, the announcement also raised new questions. How will EPA communicate the release of an MCL this fall that will likely be significantly higher than the Health Advisories for PFOA and PFOS? Also, is EPA working on a plan to test PFAS chemicals as a class? If so, the details of that will be eagerly anticipated by the regulatory community.