Contaminant Unit: ug/L

PFOS

Perfluorooctane sulfonate — one of the most studied PFAS compounds, formerly used in firefighting foam and stain-resistant coatings.

ADWG Guideline

0.07 ug/L

PFOS (perfluorooctane sulfonate) is one of the oldest and most widely studied PFAS chemicals. It was a key ingredient in aqueous film-forming foam (AFFF) used for firefighting and in stain-resistant products like Scotchgard.

Why it matters

The ADWG sets a guideline of 0.07 ug/L (70 ng/L) for PFOS — updated in 2025 from the previous value of 0.07 ug/L. PFOS is particularly concerning because:

  • It has one of the longest half-lives in the human body (approximately 5 years)
  • It is highly persistent in groundwater and does not break down
  • It has been linked to immune system effects, thyroid disruption, and some cancers in epidemiological studies

Where it’s found in Australia

The highest concentrations have been found near Defence Force bases where AFFF was used in training exercises, particularly Williamtown (NSW), Oakey (QLD), and Katherine (NT). Most urban water supplies have non-detectable PFOS levels.

Related Terms

PFAS PFOA ADWG (Australian Drinking Water Guidelines)

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Disclaimer: Glossary definitions are provided for general educational purposes only and do not constitute medical advice or professional guidance. For specific health concerns about your drinking water, consult a qualified health professional. See our Terms of Use.