Perfluorobutane Sulfonic Acid (PFBS)

Perfluorobutane sulfonic acid (PFBS) is a 4-carbon PFAS that was developed as a short-chain replacement for PFOS. 3M introduced it as a safer alternative under the brand name "Novec." However, PFBS has been found to be highly water-soluble and mobile in the environment, leading to widespread groundwater contamination. Although its individual EPA MCL is much higher (2,000 ppt) than PFOA or PFOS, PFBS is included in the hazard index rule–meaning its presence alongside other PFAS compounds counts against a combined limit. Studies show PFBS can affect thyroid hormone levels even at lower concentrations.

Where PFBS comes from

Common uses

  • Replacement for PFOS in many applications
  • Stain-resistant treatments
  • Industrial surfactants
  • Fire suppressants

Industries

  • Textiles
  • Chemical manufacturing
  • Firefighting

Health effects of PFBS exposure

Short-term effects

  • Thyroid hormone disruption

Long-term effects

  • Thyroid disease
  • Developmental neurotoxicity
  • Kidney effects

Most vulnerable populations

  • Pregnant women (fetal thyroid development)
  • Children
  • People with thyroid disorders

How to remove PFBS from drinking water

Reverse osmosis
85% removal
Activated carbon
60% removal
Ion exchange
88% removal

See filters certified to remove PFBS and other PFAS.

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