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Per- and Polyfluoroalkyl Substances (PFAS)

PFAS General

Per- and polyfluoroalkyl substances (PFAS) are a large group of human-made substances that do not occur naturally in the environment and are resistant to heat, water, and oil. PFAS have been used extensively in surface coating and protectant formulations due to their unique ability to reduce the surface tension of liquids [1]. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are two types of PFAS that are no longer manufactured or imported into the United States [2]; however, there could be some imported goods containing trace amounts of these substances[3].

Other PFAS goods and materials are still produced and used in the United States [4]. PFAS are persistent in the environment, can accumulate within the human body over time, and are toxic at relatively low concentrations [5]. Exposure to unsafe levels of PFOA/PFOS may result in adverse health effects including developmental effects to fetuses during pregnancy, cancer, liver effects, immune effects, thyroid effects, and other effects (such as cholesterol changes)[6]. PFOA and PFOS were found in the blood of nearly all people tested in several national surveys[7], [8]. According to the Center for Disease Control (CDC), blood levels of both PFOS and PFOA have steadily decreased in U.S. residents since 1999-2000[9].

PFAS can be introduced into the body by eating or drinking contaminated food or liquid (including water), breathing in or touching products treated with PFAS, such as carpets or clothing [10]. Exposure to PFOA and PFOS is generally dominated by the ingestion of food [11]. Food can be contaminated by the migration of PFAS from packaging [12], and some foods such as fish, meat, eggs and leafy vegetables may contain PFAS due to bioaccumulation and crop uptake [13].Contaminated drinking water has led to high levels of exposure to PFOA, PFOS, and other PFAS for some populations residing

near manufacturing facilities[14]. Workers in facilities that make or use PFAS can be exposed to higher amounts of these chemicals and have higher levels in their blood [15].

Infants may be exposed to PFAS through breastfeeding [16]. However, the benefits of breastfeeding are well known and generally outweigh potential risks from transfer of chemicals [17], but you can talk with your doctor if you have concerns.

PFAS, especially PFOS and PFOA, have been detected in air, water, and soil in and around manufacturing facilities; however, these releases have been declining since companies began phasing out the production and use of several PFAS in the early 2000s[18].Due to their chemical structure, PFAS are very stable in the environment and are resistant to breaking down.

Some PFAS are volatile and can be carried long distances through the air, which may lead to contamination of soils and groundwater far from the source of the PFAS emission [19]. PFAS have been detected in many parts of the world, including oceans and the Arctic, indicating that long-range transport is possible[20].

The four major sources of PFAS are: fire training/fire response sites, industrial sites, landfills, and wastewater treatment plants/biosolids[10].PFAS can get into drinking water when products containing them are used or spilled onto the ground or into lakes and rivers[21]. Once in groundwater, PFAAS are easily transported large distances and can contaminate drinking wells [10]. Substances containing PFAS can be spilled into lakes or rivers used as sources of drinking water[10]. PFAS in the air can also end up in rivers and lakes used for drinking water[10]. Additional information regarding the fate and transport of PFAS in the environment may be found on the Interstate Technology Regulatory Council fact sheet.

Potential Mechanisms of transport of PFAS from firefighting foam application to environmental media.
Potential Mechanisms of transport of PFAS from firefighting foam application to environmental media.

PFAS have been used extensively in surface coating and protectant formulations due to their unique ability to repel oil, grease and water. Major applications have included protectants for paper and cardboard packaging products, carpets, leather products, and textiles that enhance water, grease, and soil repellency, and in firefighting foams[22]. PFAS have also been used as processing aids in the manufacture of nonstick coatings on cookware[22].

Under the PFOA Stewardship Program with the U.S. Environmental Protection Agency (US EPA), eight major PFAS producers have phased out PFOA and other PFSA substances from emissions and products[2]. However, manufacturers are developing replacement technologies in the PFAS family by substituting longer-chain substances with shorter-chain substances such as GenX and ADONA [23]. While less information is available for these shorter-chain substances, studies have shown that they behave in a similar toxicological manner as their longer-chain counterparts [24], [25]. Due to the wide range of chemicals within the PFAS family and the observed similarities in their toxic mode-of-action, efforts are underway to calculate relative potency estimates for chemicals within the PFAS class in order to better inform regulation [26].

To complement the PFOA Stewardship Program, US EPA has issued regulations, known as Significant New Use Rules (SNURs), requiring manufacturers and processors of these chemicals to notify EPA of new uses of these chemicals before they are commercialized[27]. Specifically, the regulations require that anyone who intends to manufacture (including import) or process any chemicals for uses contained in the SNUR must submit a notification to EPA at least 90 days before beginning the activity[27]. This provides EPA with an opportunity to review and, if necessary, place limits on manufacturers or processors who intend to reintroduce or import products with these chemicals.

Learn more about EPA’s actions on PFASs and other perfluorinated chemicals.

[1] T. H. Begley, K. White, P. Honigfort, M. L. Twaroski, R. Neches, and R. A. Walker, “Perfluorochemicals: Potential sources of and migration from food packaging,” Food Addit. Contam., vol. 22, no. 10, pp. 1023–1031, Oct. 2005.

[2] US EPA, “PFOA Stewardship Program Docket ID Number EPA-HQ-OPPT-2006- 0621. US Environmental Protection Agency, Washington, DC.,” 2006.

[3] 3M Company, “Fluorochemical use, distribution and release overview.,” AR226-0550, 1999.

[4] H. Lee, J. D’eon, and S. A. Mabury, “Biodegradation of Polyfluoroalkyl Phosphates as a Source of Perfluorinated Acids to the Environment,” Environ. Sci. Technol., vol. 44, no. 9, pp. 3305–3310, May 2010.

[5] Z. Wang, J. C. DeWitt, C. P. Higgins, and I. T. Cousins, “A Never-Ending Story of Per- and Polyfluoroalkyl Substances (PFASs)?,” Environ. Sci. Technol., vol. 51, no. 5, pp. 2508–2518, Mar. 2017.

[6] ATSDR, “Toxicological Profile for Perfluoroalkyls, Draft for Public Comment,” 2018.

[7] A. M. Calafat, L.-Y. Wong, Z. Kuklenyik, J. A. Reidy, and L. L. Needham, “Polyfluoroalkyl Chemicals in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 and Comparisons with NHANES 1999–2000,” Environ. Health Perspect., vol. 115, no. 11, pp. 1596–1602, Nov. 2007.

[8] J. M. Graber et al., “Per and polyfluoroalkyl substances (PFAS) blood levels after contamination of a community water supply and comparison with 2013–2014 NHANES,” J. Expo. Sci. Environ. Epidemiol., vol. 29, no. 2, pp. 172–182, Mar. 2019.

[9] CDC, “National Report on Human Exposure to Environmental Chemicals,” 2019.

[10] E. M. Sunderland, X. C. Hu, C. Dassuncao, A. K. Tokranov, C. C. Wagner, and J. G. Allen, “A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects,” J. Expo. Sci. Environ. Epidemiol., vol. 29, no. 2, pp. 131–147, Mar. 2019.

[11] L. S. Haug, S. Huber, G. Becher, and C. Thomsen, “Characterisation of human exposure pathways to perfluorinated compounds — Comparing exposure estimates with biomarkers of exposure,” Environ. Int., vol. 37, no. 4, pp. 687–693, May 2011.

[12] L. A. Schaider et al., “Fluorinated compounds in US fast food packaging,” Environ. Sci. Technol. Lett., vol. 4, no. 3, pp. 105–111, 2017.

[13] H. Zhang, R. Vestergren, T. Wang, J. Yu, G. Jiang, and D. Herzke, “Geographical Differences in Dietary Exposure to Perfluoroalkyl Acids between Manufacturing and Application Regions in China,” Environ. Sci. Technol., vol. 51, no. 10, pp. 5747–5755, 2017.

[14] X. C. Hu et al., “Detection of poly-and perfluoroalkyl substances (PFASs) in US drinking water linked to industrial sites, military fire training areas, and wastewater treatment plants,” Environ. Sci. Technol. Lett., vol. 3, no. 10, pp. 344–350, 2016.

[15] F. A. Ubel, S. D. Sorenson, and D. E. Roach, “Health status of plant workers exposed to fluorochemicals - a preliminary report,” Am. Ind. Hyg. Assoc. J., vol. 41, no. 8, pp. 584–589, Aug. 1980.

[16] P. Grandjean et al., “Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years,” J. Immunotoxicol., vol. 14, no. 1, pp. 188–195, Jan. 2017.

[17] M. N. Mead, “Contaminants in Human Milk: Weighing the Risks against the Benefits of Breastfeeding,” Environ. Health Perspect., vol. 116, no. 10, Oct. 2008.

[18] J. M. Armitage, M. MacLeod, and I. T. Cousins, “Modeling the Global Fate and Transport of Perfluorooctanoic Acid (PFOA) and Perfluorooctanoate (PFO) Emitted from Direct Sources Using a Multispecies Mass Balance Model,” Environ. Sci. Technol., vol. 43, no. 4, pp. 1134–1140, Feb. 2009.

[19] M. F. Rahman, S. Peldszus, and W. B. Anderson, “Behaviour and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water treatment: A review,” Water Res., vol. 50, pp. 318–340, Mar. 2014.

[20] F. Wong et al., “Assessing temporal trends and source regions of per- and polyfluoroalkyl substances (PFASs) in air under the Arctic Monitoring and Assessment Programme (AMAP),” Atmos. Environ., vol. 172, pp. 65–73, Jan. 2018.

[21] E. Hepburn, C. Madden, D. Szabo, T. L. Coggan, B. Clarke, and M. Currell, “Contamination of groundwater with per- and polyfluoroalkyl substances (PFAS) from legacy landfills in an urban re-development precinct,” Environ. Pollut., vol. 248, pp. 101–113, May 2019.

[22] E. Kissa, Fluorinated surfactants and repellents, vol. 97. CRC Press, 2001.

[23] R. Renner, “The long and the short of perfluorinated replacements,” Environ. Sci. Technol., vol. 40, no. 1, pp. 12–13, Jan. 2006.

[24] S. C. Gordon, “Toxicological evaluation of ammonium 4,8-dioxa-3H-perfluorononanoate, a new emulsifier to replace ammonium perfluorooctanoate in fluoropolymer manufacturing,” Regul. Toxicol. Pharmacol., vol. 59, no. 1, pp. 64–80, 2011.

[25] Z. Wang, I. T. Cousins, M. Scheringer, and K. Hungerbuehler, “Hazard assessment of fluorinated alternatives to long-chain perfluoroalkyl acids (PFAAs) and their precursors: Status quo, ongoing challenges and possible solutions,” Environ. Int., vol. 75, pp. 172–179, Feb. 2015.

[26] J. Lijzen, “Mixture exposure to PFAS: A Relative Potency Factor approach,” National Institute for Public Health and the Environment, RIVM Report 2018-0070.

[27] USEPA, “Perfluoroalkyl Sulfonates; Significant New Use Rule,” Fed. Regist., vol. 67, no. 236, pp. 72854–72867, 2002.

Additional efforts in California by other CalEPA agencies are included below:

Important Links

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.

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.

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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