Perfluorononane Sulfonic Acid (PFNS)

Perfluorononane sulfonic acid (PFNS) is a 9-carbon sulfonated PFAS monitored under UCMR5. It is less commonly detected than PFOS or PFHxS but has been found at industrial and military contamination sites. Like other long-chain sulfonated PFAS, PFNS is expected to be highly persistent and bioaccumulative. Its 9-carbon chain length suggests significant bioaccumulation potential similar to PFDA. Limited toxicological studies exist specifically for PFNS, but its structural characteristics suggest risks similar to PFOS.

Where PFNS comes from

Common uses

  • Specialty industrial surfactants
  • Fluoropolymer processing

Industries

  • Chemical manufacturing

Health effects of PFNS exposure

Short-term effects

  • Liver enzyme changes expected at high doses

Long-term effects

  • Expected bioaccumulation
  • Potential immune and liver effects

Most vulnerable populations

  • People near industrial PFAS sites

How to remove PFNS from drinking water

Reverse osmosis
95% removal
Activated carbon
83% removal
Ion exchange
95% removal

See filters certified to remove PFNS and other PFAS.

Is PFNS in your water? – Enter your ZIP at KnowYourExposure to see your local EPA test results.