PFAS - What Are They?

What Are PFAS? Per- and polyfluoroalkyl substances (PFAS) are a group of manufactured (synthetic) chemicals used worldwide since the 1950s to make fluoropolymer coatings and products that resist heat, oil, stains, grease, and water. During production and use, PFAS can migrate into the soil, water, and air. Most PFAS do not break down; they remain in the environment, ultimately finding their way into drinking water. Because of their widespread use and their persistence in the environment, PFAS are found in the blood of people and animals and in water, air, fish and soil all over the world at low levels. Some PFAS can build up in people and animals with repeated exposure over time.

 The most commonly studied PFAS are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). PFOA and PFOS have been phased out of production and use in the United States, but other countries may still manufacture and use them.

 Some products that may contain PFAS include:

  • Some grease-resistant paper, fast food containers/wrappers, microwave popcorn bags, pizza boxes
  • Nonstick cookware
  • Stain-resistant coatings used on carpets, upholstery, and other fabric
  • Water-resistant clothing
  • Personal care products (shampoo, dental floss) and cosmetics (nail polish, eye makeup)
  • Cleaning products
  • Firefighting foams
  • Paints, varnishes, and sealants

 Even though recent efforts to remove PFAS from manufacturing process have reduced the likelihood of exposure, some products may still contain them. If you have questions or concerns about products you use in your home, contact the Consumer Product Safety Commission at (800) 638-2772. For a more detailed discussion on PFAS, please visit

City of Napa PFAS test results

The City of Napa is well aware of PFAS and the latest challenges and testing needs for these forever chemicals and are fortunate to not have industrial processes within our local watersheds like some communities.  We are also closely following PFAS research as analytical laboratories are still developing consistent, reliable sampling and testing methods at extremely low-levels at which future drinking water regulations for these compounds are going to be set.

Under the Safe Drinking Water Act, the USEPA requires priority unregulated contaminants be monitored by water systems.  While these parameters may be present in some drinking water they are not yet subject to drinking water standards.  If contaminants are not found, consumer confidence in their drinking water should improve.  If contaminants are found, related health effects associated with drinking water may be avoided when subsequent actions, such as regulations, are implemented, reducing or eliminating those contaminants.

For the current Fifth Unregulated Contaminant Monitoring Rule the City of Napa has tested for 29 PFAS in the drinking water in January and April 2023 with all results as “none detected.”  Quarterly sampling will continue through October 2023 and test results will be promptly updated.