Past PFOA and PFOS Health Effects Science Documents

On April 10, 2024, the EPA published the final human health toxicity assessments for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) and the final PFAS National Primary Drinking Water Rule (NPDWR). PFOA and PFOS are members of a chemical group called per- and polyfluoroalkyl substances (PFAS). The final PFOA and PFOS toxicity assessments report toxicity values that reflect the best available health effects information.

The EPA published the 2022 PFOA and PFOS interim drinking water health advisories (iHAs) to provide timely, health-based information that was based on updated toxicity information published since the 2016 PFOA and PFOS HAs. The 2022 PFOA and PFOS interim HAs no longer reflect the best available scientific information because they were based on draft noncancer toxicity values from the 2021 SAB review drafts of the PFOA and PFOS toxicity assessments. The final EPA toxicity values in the 2024 PFOA and PFOS toxicity assessments reflect the best available science and are different from the 2021 draft toxicity values used to calculate the 2022 interim HAs.

The EPA is providing the earlier health effects science documents, published between 2009 and 2022, for historical reference purposes.

2022 Interim Updated PFOA and PFOS Health Advisories

On June 15, 2022, the EPA issued interim updated drinking water iHAs for PFOA and PFOS that replaced those the EPA issued in 2016.

At the same time, the EPA also issued final HAs for two other PFAS, perfluorobutane sulfonic acid and its potassium salt (PFBS) and for hexafluoropropylene oxide dimer acid (HFPO-DA) and its ammonium salt (“GenX chemicals"). In chemical and product manufacturing, GenX chemicals are considered a replacement for PFOA, and PFBS is considered a replacement for PFOS.

• Federal Register Notice on Lifetime Drinking Water Health Advisories for Four Perfluoroalkyl Substances (June 21, 2022)
• Interim Drinking Water Health Advisory: Perfluorooctanoic Acid (PFOA) CASRN 335-67-1 (pdf) (612.13 KB, June 2022, EPA 822-R-22-003)
  • External Peer Review Draft: Proposed Approaches to the Derivation of a Draft Maximum Contaminant Level Goal for Perfluorooctanoic Acid (PFOA) (CASRN 335-67-1) in Drinking Water) (December 2021, EPA 822-D-21-001)
• Interim Drinking Water Health Advisory: Perfluorooctane Sulfonic Acid (PFOS) CASRN 1763-23-1 (pdf) (622.38 KB, June 2022, EPA 822-R-22-004)
  • External Peer Review Draft: Proposed Approaches to the Derivation of a Draft Maximum Contaminant Level Goal for Perfluorooctane Sulfonic Acid (PFOS) (CASRN 1763-23-1) in Drinking Water (December 2021, EPA 822-D-21-002)

2016 PFOA and PFOS Health Advisories

• FR Notice on the Health Advisories for PFOA and PFOS (May 25, 2016)
• 2016 PFOA Health Advisory (pdf)
• 2016 PFOA Health Effects Support Document (pdf)
• 2016 PFOS Health Advisory (pdf)
• 2016 PFOS Health Effects Support Document (pdf)
• 2016 EPA Response to Peer Review Comments (pdf)
• Peer Reviewer Summary Report: External Peer Review of EPA’s Draft Health Effects Documents for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS)

2009 Provisional Health Advisories

• 2009 Provisional Health Advisories for PFOA and PFOS (pdf)