Aquatic Life Criteria - Perfluorooctane Sulfonate (PFOS)
What is Perfluorooctane Sulfonate (PFOS)?
PFOS belongs to the per- and polyfluorinated substances (PFAS) group of chemicals. PFOS is an organic, human-made perfluorinated compound, consisting of an eight-carbon backbone and a sulfonate functional group. Commercial production and use of PFOS for surface treatments for soil and stain resistance of textiles, paper, metals, pesticides, and is use in applications such as in firefighting foams started in the mid-1950s.
How does PFOS affect Aquatic Life?
PFOS is human-made molecule and has no biologically important functions or beneficial properties to aquatic life. The mechanisms underpinning the toxicity of PFOS to aquatic organisms, like other PFAS, is an active and on-going area of research. Much work is still needed from a mechanistic perspective to better understand how the different modes of action elicit specific biological responses. The draft aquatic life ambient water quality criteria are based on observed effects of PFOS to the survival, growth, and reproduction of aquatic organisms.
2022 Draft Aquatic Life Criteria for Perfluorooctane Sulfonate (PFOS)
The extended public comment period for the published draft national recommended aquatic life criteria for PFOS closed on July 5, 2022.
These draft criteria reflect the latest scientific knowledge regarding the effects of PFOS on freshwater organisms. The draft PFOS criteria document contains acute and chronic criteria for freshwaters. The draft criteria document also contains chronic criteria expressed as tissue-based concentrations to protect aquatic life from PFOS bioaccumulation. The chronic freshwater and chronic tissue criteria are intended to be independently applicable and no one criterion takes primacy.
Once finalized, states and authorized tribes can adopt these recommended criteria into water quality standards to protect against harmful effects of PFOS on aquatic life.
Available PFOS toxicity data for estuarine/marine species allowed for the derivation acute estuarine/marine benchmarks through application of a New Approach Method (NAM). The acute estuarine/marine benchmark is also intended to be protective of aquatic life designated uses.
- Memorandum: Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS); Extension of Comment Period (June 28, 2022)
- Federal Register Notice: Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS); Extension of Comment Period (May 31, 2022)
- Federal Register Notice: Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS) for public comment (May 3, 2022)
- Fact Sheet: Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS)
- Document: 2022 Draft Aquatic Life Ambient Water Quality Criteria Recommendations for Perfluorooctane Sulfonate (PFOS)
- External Peer Review Comments on the Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS) (pdf)
- EPA 2022 Response to External Peer Review Comments on the Draft Aquatic Life Ambient Water Quality Criteria for Perfluorooctane Sulfonate (PFOS) (pdf)