Environmental Alert
(by Matt Wood and Mackenzie Moyer)
On May 18, 2022, the U.S. Environmental Protection Agency (EPA) added five per- and polyfluoroalkyl substances (PFAS) to its Regional Screening Level (RSL) and Regional Removal Management Level (RML) lists, increasing the total number of PFAS chemicals from one to six. The five added PFAS chemicals EPA are:
- Hexafluoropropylene oxide dimer acid and its ammonium salt (HFPO-DA, a/k/a GenX);
- Perfluorooctanesulfonic acid (PFOS);
- Perfluorooctanoic acid (PFOA);
- Perfluorononanoic acid (PFNA); and
- Perfluorohexanesulfonic acid (PFHxS).
These join perfluorobutanesulfonic acid (PFBS), which EPA added to the RSL and RML lists in 2014 (and revised in 2021 with an updated toxicity assessment). The RSLs and RMLs are not cleanup standards; they are risk-based values used to identify contamination and inform whether additional actions may be necessary at a given site to protect human health and the environment. Specifically, EPA utilizes RSLs to identify whether contaminated media at a given site should be further investigated (e.g., if a constituent’s concentration exceeds the RSL, it likely requires additional investigation; concentrations below the RSL generally do not). RMLs are one of many factors EPA uses to support a decision whether to conduct a removal action at a site. The updated RSL tables are available here and the RML tables are available here.
More broadly, these updates are among many PFAS-related steps EPA has taken or intends to take in the coming months and years. They follow three actions, described below, that EPA took in April 2022 to address PFAS in water.
- To better investigate and analyze PFAS in water, EPA published its Draft Method 1621, a screening method capable of measuring aggregated concentrations of chemicals with carbon-fluorine bonds at the parts per billion level, i.e., it measures concentrations of PFAS, as well as non-PFAS fluorinated compounds, such as pesticides and pharmaceuticals.