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PFOS is a chemical used as a surfactant in a variety of industrial and commercial products such as food packaging, stain and water-resistant materials, fire-fighting foams and paint additives. The likely environmental sources are from introduction via commercial production or during use (such as with fire-fighting foams). PFOS is frequently detected in biota (99% of samples in one study) but less often in surface waters and sediments (detected in 25% of water samples and approximately 84% of sediment samples). It is typically detected near a production or use site.

Environmental implications of PFOS

  • Toxic to aquatic organisms, and the concentrations detected in surface waters in Minnesota could cause endocrine effects in aquatic organisms.
  • Because it has the potential to bioconcentrate, secondary poisoning to wildlife eating aquatic organisms should be considered. Concentrations observed in fish tissue in Minnesota are high enough that toxic effects are possible due to secondary poisoning to terrestrial animals that eat fish.
  • Accumulates and is persistent in sediment. It has been detected in sediment in Minnesota, but there are no toxicity studies that evaluate the risk to sediment-dwelling aquatic life at the levels observed.
  • Highly volatile and is persistent in air, so long-range atmospheric transport of this contaminant is a concern. It has been hypothesized that the PFOS detected in the tissues of arctic seals arrived via atmospheric transport.

Toxic mode of action

The mode of action of toxicity due to PFOS exposure in aquatic life is unknown.

Relevant media for monitoring

Biota, water, sediment

Are there seasonal considerations for monitoring?

No. PFOS was a widely used chemical and is persistent, so it is likely to be found in water and tissue year-round.

Important degradates

Degradates have not been identified. PFOS is very persistent and may have limited degradation.


Because this contaminant is persistent, bioaccumulative and toxic, continued monitoring of PFOS is recommended. Biota and sediment should be monitored because PFOS has been demonstrated to accumulate in both.

CAS RN: 1763-23-1

Alternate name(s): PFOS

Primary use(s): Industrial chemical

Priority: High