EPA is taking an important step forward to protect people from per- and polyfluoroalkyl substances (PFAS) by adding five PFAS chemicals for a total of six PFAS chemicals to a list of risk-based values that help EPA determine if response or remediation activities are needed. EPA’s action provides the Agency with critical tools needed for Superfund and other Agency programs to investigate contamination and protect people from these PFAS chemicals using the latest peer-reviewed science.
“Aggressively addressing PFAS across America is an active and ongoing priority to the Biden-Harris Administration,” said Carlton Waterhouse, EPA Deputy Assistant Administrator for the Office of Land and Emergency Management. “One key way that EPA is leading this effort is by relying on sound science to investigate risk from PFAS at Superfund sites.”
Screening and removal management levels are not cleanup standards. They are risk-based values that help EPA determine if further investigation or actions are needed to protect public health, such as, sampling, assessing risks, and taking further action, which could include providing alternative drinking water. These mechanisms allow site teams to make better site decisions that will 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), and perfluorohexanesulfonic acid (PFHxS). EPA added the first PFAS substance, PFBS or perfluorobutanesulfonic acid, to the Regional Screening Level and Regional Removal Management Level lists in 2014 and updated it in 2021 when EPA released its updated toxicity assessment for PFBS.
The science of PFAS is rapidly evolving. For PFOA, PFOS, PFNA, and PFHxS, EPA selected levels using the most updated final peer-reviewed information based on Minimal Risk Levels from the Agency for Toxic Substances and Disease Registry’s 2021 toxicological profile. For the fifth chemical, HFPO-DA, EPA used a final peer-reviewed EPA toxicity value. EPA regularly reviews and updates Regional Screening Levels and Regional Removal Management Levels twice a year. As the science on PFAS evolves, EPA may update these values and add other PFAS chemicals.
Regional Screening Levels are used to identify contaminated media (i.e., 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 EPA’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, EPA is moving as quickly as possible to update the interim health advisories for PFOA and PFOS to reflect new science and input from the Science Advisory Board. Concurrently, EPA will continue to develop a proposed PFAS National Drinking Water Regulation for publication in fall 2022. EPA anticipates finalizing the rule in fall of 2023.
For more information for risk assessors:
- “What’s New” section on the Regional Screening Levels webpage.
- Regional Screening Levels: https://www.epa.gov/risk/regional-screening-levels-rsls
- Regional Removal Management Levels: https://www.epa.gov/risk/regional-removal-management-levels-chemicals-rmls
For more information about EPA’s work to address PFAS, please visit: https://www.epa.gov/pfas