The U.S. Environmental Protection Agency (USEPA) recently added five per- and polyfluoroalkyl substances (PFAS) chemicals, for a total of six PFAS chemicals, to a list of risk-based values that help USEPA determine if response or remediation activities are needed. The addition of the five chemicals provides critical tools needed for USEPA programs to investigate contamination and protect people from the effect of PFAS chemicals.
Screening and removal management levels are not intended as cleanup standards. Rather, they are risk-based values that help USEPA determine if further investigation or actions are needed to protect public health by conducting sampling and assessing risks. These mechanisms allow site teams to make better decisions to protect nearby communities.
The five PFAS additions include:
• hexafluoropropylene oxide dimer acid and its ammonium salt (HFPO-DA – sometimes referred to as GenX chemicals)
• perfluorooctanesulfonic acid (PFOS)
• perfluorooctanoic acid (PFOA)
• perfluorononanoic acid (PFNA)
• perfluorohexanesulfonic acid (PFHxS)
Perfluorobutanesulfonic acid (PFBS) has been on the list since 2014 and was updated in 2021 when the USEPA released its updated toxicity assessment for PFBS.
Regional Screening Levels are used to identify contaminated air, tap water, and soil at a site that may need further investigation. In general, if a contaminant concentration is below the screening level, no further action or investigation is needed. If the concentration is above the screening level, further investigation is generally needed to determine if some action is required. Regional Removal Management Levels are used to support USEPA’s decisions to undertake a removal action under CERCLA, such as providing alternative drinking water, or remediation of contaminated media, if necessary.
In addition to updating the Regional Screening Levels and Regional Removal Management Levels, USEPA intends to update the interim health advisories for PFOA and PFOS to reflect new science and input from the Science Advisory Board. Concurrently, USEPA will continue to develop a proposed PFAS National Drinking Water Regulation for publication in fall 2022 and anticipates finalizing the rule in fall of 2023.