Perfluoroheptanoic Acid (PFHpA)

Perfluoroheptanoic acid (PFHpA) is a 7-carbon PFAS carboxylate that has been found in drinking water across the United States. It is often detected alongside other PFAS compounds at industrial and military sites. PFHpA is part of the EPA's 2024 hazard index rule, which recognizes that mixtures of PFAS can have additive harmful effects even when individual compound levels are below standalone limits. Research on PFHpA is still developing, but animal studies suggest thyroid and liver effects similar to other long-chain PFAS.

Where PFHpA comes from

Common uses

  • Industrial surfactants
  • Fluoropolymer processing
  • Paper coatings

Industries

  • Chemical manufacturing
  • Paper industry

Health effects of PFHpA exposure

Short-term effects

  • Liver enzyme changes

Long-term effects

  • Liver toxicity
  • Thyroid disruption
  • Developmental effects

Most vulnerable populations

  • Pregnant women
  • Children
  • People with liver disease

How to remove PFHpA from drinking water

Reverse osmosis
91% removal
Activated carbon
74% removal
Ion exchange
90% removal

See filters certified to remove PFHpA and other PFAS.

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