Per- and Polyfluoroalkyl Substances (PFAS)
What is PFAS?
Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are fluorinated organic chemicals that are part of a larger group of man-made chemicals referred to as per-and polyfluoroalkyl substances (PFAS), which are generally resistant to heat, water, and oil. They have been used extensively in consumer products such as carpets, clothing, fabrics for furniture, paper packaging for food, fire-fighting foams, and other materials (e.g., cookware) designed to be water proof, stain-resistant or non-stick.
These chemicals are persistent, which means they do not break down in the environment. Some PFAS can also bioaccumulate, meaning the amount builds up over time in the blood and organs. Studies in animals who were exposed to PFAS found links between the chemicals and increased cholesterol, changes in the body’s hormones and immune system, decreased fertility, and increased risk of certain cancers.
How can PFAS affect me?
PFAS can get into drinking water when products containing them are used or spilled onto the ground or into lakes and rivers. PFAS move easily through the ground, getting into ground water that may be used for water supplies or for private drinking water wells. Such contamination is typically localized and associated with a specific facility, such as an industrial facility where these chemicals were manufactured or used in other products, or an air field which used the chemicals for firefighting. People can also be exposed to PFAS through food, food packaging, consumer products, and house dust.
What has been done?
Between 2000 and 2002, PFOS was voluntarily phased out of production in the U.S. by its primary manufacturer. Beginning in 2006 other manufacturers began to voluntarily limit the number of on-going uses. Although most of the PFAS chemicals are no longer manufactured in the United States, other countries still produce PFOA and PFOS and products that contain them may be imported, such as carpets, leather and apparel, textiles, paper and packaging, coatings, rubber, and plastics.
PFOA and PFOS Notification Levels:
In May 2016, the United States Environmental Protection Agency (U.S.EPA) issued a lifetime health advisory for PFOS and PFOA for drinking water, advising municipalities that they should notify their customers of the presence of levels over 70 parts per trillion in community water supplies. U.S.EPA recommended that customer notifications include information on the increased risk to health, especially for susceptible populations.
In June 2018, California’s Office of Environmental Health Hazard Assessment (OEHHA) recommended interim notification levels for PFOA (based on liver toxicity, as well as cancer risks), and for PFOS (based on immunotoxicity). OEHHA made these recommendations following its review of currently available health-based advisories and standards and supporting documentation. After independent review of the available information on the risks, the Water Board Division of Drinking Water (DDW) established notification levels for PFOS and PFOA (13 parts per trillion for PFOS and 14 parts per trillion for PFOA), as well as a single health advisory response level which offers a margin of protection for all persons throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water. When possible, DDW recommends removing the source from service or providing treatment when the concentration exceeds a notification level. DDW recommends removing the source from service when the concentration level cannot be reduced below the response level of 70 ppt.
Additional efforts in California by other CalEPA agencies are included below:
Frequently Asked Questions (FAQs)
- Laboratories Accredited to Analyze for PFAs in Drinking Water by EPA Method 537 Revision 1.1
- Drinking Water Sample Collection for PER and POLYFLUORINATED ALKYL SUBSTANCES (PFAS) Sampling Guidance
- Drinking Water Sources FAQ (Coming Soon)
- Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS)
- Division of Drinking Water
- Drinking Water Systems - Information
Testing in California Drinking Water
From 2013 to 2015, the US EPA, under the Unregulated Contaminant Monitoring Rule (UCMR 3), required all large water systems (i.e., water systems serving over 10,000 people) to collect and analyze more than 12,000 drinking water samples for PFOS and PFOA. In addition, some water systems serving less than 10,000 people reported approximately 400 drinking water results for PFOS and PFOA. This occurrence data identified 36 sources with PFOS detections and 32 sources with PFOA detections. A summary of the findings for California is available here.
In May 2016, the US EPA has established a lifetime Health Advisory Level (HAL) for PFOA and PFOS of 70 ng/L. When both PFOA and PFOS are found in drinking water, the combined concentrations of PFOA and PFOS should be compared with the 70 ng/L HAL.
In June 2018, OEHHA recommend interim notification levels for PFOA (based on liver toxicity, as well as cancer risks) and for PFOS (based on mmunotoxicity). OEHHA made these recommendations following its review of currently available health-based advisories and standards and supporting documentation. After independent review of the available information on the risks, DDW established notification levels at concentrations of 13 parts per trillion for PFOS and 14 parts per trillion for PFOA. These levels are consistent with OEHHA’s recommendations. When the NLs are exceeded, the DDW recommends that the source be removed from service and treated. When the RL is exceeded, and concentrations cannot be reduced below the US EPA HAL, DDW recommends removing the source from service.
Testing Methods in California Drinking Water
Some analytical methods using liquid chromatography-mass spectrometry-electrospray ionization methods (LC/MS/ESI) can achieve reporting limits for PFOA and PFOS at the nanogram per liter (ng/L) level. For the UCMR 3 monitoring program, LC/MS/MS-EPA Method 537 (rev 1.1) was required with minimum reporting limits of 20 ng/L and 40 ng/L for PFOA and PFOS, respectively. In November 2018, revised US EPA Method 537.1 was published that can detect PFOA, PFOS, and 16 other per-and polyfluorinated alkyl substances. Compliance with the recent NLs of 14ng/L (PFOA) and 13 ng/L (PFOS) will require reporting limits lower than what can be achieved with EPA 537. US EPA Method 537.1 is reported tobe able to achieve lowest concentration minimum reporting levels (LCMRL)of 0.82 ng/L (PFOA) and 2.7 ng/L (PFOS). An LCMRL is defined as the lowest true concentration for which the future recovery is predicted to fall, with 99% confidence, between 50 and 150% recovery of the matrix spike (USEPA, Method 537.1, 2018).
Further information regarding PFAS in drinking water may be found at the Division of Drinking Water PFOA/PFOS webpage.
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- New! March 20, 2019 PFAS General Sampling Guide
- March 6, 2019 PFAS Informational Item
- Feb 14, 2019: US EPA announcements PFAS action Plan
- July 13, 2018: "State Water Board Release Guidelines for Testing and Reporting on PFOA and PFOS in Drinking Water"