Nutrasource Blog

What are PFAS and how am I exposed to them?

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that have been used in various products since the 1940s. The definition of PFAS varies according to different regulatory agencies, but in general PFAS contain chains of carbon molecules with varying numbers of fluorine molecules attached to the carbons. They are known as “forever chemicals” because of their resistance to breaking down and have been shown to be hazardous to humans and other species.

Because PFAS can repel water, grease, and oil, they have been used in cosmetics, personal care products, cookware, food packaging, food processing equipment, stain- and water-resistant fabrics and carpeting, cleaning products, paints, and fire-fighting foams. There is widespread contamination of PFAS in the environment because of their extensive use and resistance to degradation. PFAS can be released into soil, air, and water and oral exposure can arise from drinking water or ingesting foods that are contaminated with or wrapped in packaging that contains PFAS.

There are many chemicals that are categorized as PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) (See Figure 1). These two chemicals are among the most investigated types of PFAS, and therefore regulatory agencies have focused their efforts on determining limits for these two substances. In 2020, EFSA published the results of a risk assessment of PFAS in food¹. The risk assessment was conducted using the sum of four PFAS: PFOA, perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and PFOS. Exposure data from 16 European countries were analyzed. For PFOS and PFOA, “fish and other seafood” were the primary dietary sources of exposure. Eggs and egg products, meat and meat products, and fruit and fruit products also contributed to intake of these substances.

Figure 1. Structures of PFOA (left) and PFOS (right) (2)

What do PFAS do in humans and what are safe levels?

PFAS are associated with increased serum cholesterol and immunosuppression in humans and a number of different adverse effects in rodents, including tumor promotion and developmental toxicity¹. In 2018, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) determined that based on available data, the tolerable weekly intakes (TWIs) of PFOS and PFOA were 13 and 6 ng/kg bw, respectively². These values are slightly lower than the minimum risk levels (MRLs) for intermediate oral intake of PFOS and PFOA that were established by the US-based Agency for Toxic Substances and Disease Registry (ATSDR) in 2021 (2 ng PFOS/kg per day and 3 ng PFOA/kg per day, which would be 14 and 21 ng/kg bw/week, respectively)³. ATSR also derived intermediate oral intake MRLs for PFHxS (20 ng/kg per day) and PFNA (3 ng/kg per day). ATSDR MRLs for PFAS are low compared to most chemicals evaluated by ATSR⁴.

As a result of their 2020 risk assessment¹, EFSA established a TWI of 4.4 ng/kg bw for the sum of PFOA, PFNA, PFHxS and PFOS, which is lower than their previously established TWIs for either PFOS or PFOA (see above). This decision was based on the conclusion that adverse effects on the immune system were the most critical for the risk assessment of these chemicals. EFSA noted that PFOS (possibly to a greater extent than PFOA) resulted in immunosuppression, which could lead to a decrease in resistance to infection. The TWI of 4.4 ng/kg bw is expected to protect mothers from reaching a total body amount of PFAS that has the potential to result in adverse effects on antibody titers in infants. A dietary intake assessment included in the EFSA document showed that the TWI was likely exceeded in a significant number of Europeans.

What is being done about PFAS?

Limits of both PFOA and PFOS have been established for drinking water in many developed countries, and the World Health Organization (WHO) has developed a draft provisional guideline value of 100 ng/L (ppt) for PFOA and PFOS (individually) in drinking water⁵. Guidance values established by Health Canada and legally enforceable levels established by US Environmental Protection Agency (EPA) for PFAS in drinking water are lower than this value (Health Canada: 30 ppt sum of 25 different PFAS, EPA: 4 ppt individually for PFOA/PFOS and 10 ppt individually for PFHxS/PFNA/ hexafluoropropylene oxide dimer acid (HFPO-DA))^6,7.

FDA and USDA started analyzing food, meat, poultry and fish samples for PFAS in 2019. In the 2021 Total Dietary Study conducted by FDA, PFAS were detected in 6/92 samples (beef, shrimp, salmon, catfish, cod, and tilapia)⁸. Knowing that filter feeders, such as clams, oysters, mussels, and scallops, have the potential to bioaccumulate more environmental contaminants than other seafood types, FDA is conducting additional sampling of filter feeders (including imported and domestic clams) to better understand PFAS in commercially available seafood and has refused entry of shipments of imported clams with high PFAS levels⁸. In February 2024, FDA announced that substances containing PFAS used as grease-proofing agents on paper and paperboard for food contact use are no longer being sold by manufacturers into the U.S. market, and in January 2025, FDA issued a Notice in the Federal Register announcing that food contact notifications (FCNs) related to PFAS-containing food contact substances as grease-proofers applied to paper and paperboard food packaging are no longer effective based on the abandonment of these uses⁹. In the US, packaging for pizza and fast food has undergone changes in recent years based on market phase-out of PFAS. 

What can I do to limit exposure or effects of PFAS?

It is expected that phase-outs and limits for PFAS in drinking water will eventually reduce exposures to acceptable levels; however, this may take years due to persistence of these substances in the environment. Although seafood is a known source of PFAS in the diet, FDA has reiterated that seafood should be included as part of a healthy diet¹⁰. Clinical studies have shown that diets high in fruit or fiber are associated with lower serum PFAS concentrations^11-13. Take steps to support your immune system to help counteract the immunosuppressant effects of PFAS.

How SGS Nutrasource Can Help

For companies navigating the complexities of PFAS regulation and contamination risk, trusted scientific expertise is required. SGS Nutrasource offers comprehensive analytical testing, regulatory consulting, and safety assessment services to help companies in the food, dietary supplement, and pharmaceutical industries ensure product safety and compliance. With a team of regulatory specialists and access to laboratories globally, we support brands in identifying, managing, and minimizing PFAS exposure in their supply chains. Whether you need guidance on regulatory limits, testing strategies, or consumer safety, SGS Nutrasource is your partner in building trust through science.

About the Author

With over 30 years of experience as a toxicologist, Dolan is responsible for scientific research and generation of safety dossiers related to GRAS, NDIN and safety assessments at GRAS Associates, a SGS Nutrasource Company.   Dolan is a Diplomate of the American Board of Toxicology (DABT), Fellow of the American College of Nutrition (FACN) and a past president of the Food Safety Specialty Section of the Society of Toxicology (SOT), bringing a wealth of knowledge and skill to the GRAS Associates team.   Prior to joining SGS Nutrasource, Dolan was most recently employed as a Senior Toxicologist in the Contaminant Assessment Branch at the FDA Center for Food Safety and Nutrition, where she routinely performed risk assessments for metal, toxin, chemical and pesticide contaminants. Dolan also has experience working as a consulting toxicologist, and a toxicologist for Procter and Gamble. She received her Bachelor of Science in Chemistry from SUNY Oswego before completing her PhD in Pharmacology/Toxicology at Michigan State University.

References

1. EFSA (2020). Risk to human health related to the presence of perfluoroalkyl substances in food. (see https://doi.org/10.2903/j.efsa.2020.6223).
2. EFSA (2018). Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food (see https://doi.org/10.2903/j.efsa.2018.5194).
3. ATSDR (2021). Toxicological profile for perfluoroalkyls (see https://www.atsdr.cdc.gov/ToxProfiles/tp200.pdf).
4. ATSDR (2025). Minimal risk levels (MRLs) for hazardous substances (see https://wwwn.cdc.gov/TSP/MRLS/mrlsListing.aspx).
5. WHO (2022). PFOS and PFOA in Drinking-water. Background document for development of WHO Guidelines for Drinking-water Quality. Draft for Public View (see https://www.cmbg3.com/library/WHO-Draft-Drinking-Water-Document.pdf).
6. Health Canada (2024). Objective for Canadian drinking water quality. Per- and polyfluoroalkyl substances (see objective-for-canadian-drinking-water-quality-en-final.pdf).
7. EPA (2024). Per- and polyfluoroalkyl substances (PFAS). Final PFAS national primary drinking water regulation (see https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas).
8. FDA (2025). Analytical results of testing food for PFAS from environmental contamination (see https://www.fda.gov/food/environmental-contaminants-food/analytical-results-testing-food-pfas-environmental-contamination).
9. FDA (2025). Questions and answers on PFAS in food (see Questions and Answers on PFAS in Food | FDA).
10. FDA (2022). FDA shares results on PFAS testing in seafood (see FDA Shares Results on PFAS Testing in Seafood | FDA).
11. Sultan H, Buckley JP, Kalkwarf HJ, Cecil KM, Chen A, Lanphear BP, Yolton K, Braun JM. (2023). Dietary per- and polyfluoroalkyl substance (PFAS) exposure in adolescents: The HOME study. Environ Res. 231(1):115953.
12. Lin PD, Cardenas A, Hauser R, Gold DR, Kleinman KP, Hivert MF, Fleisch AF, Calafat AM, Sanchez-Guerra M, Osorio-Yáñez C, Webster TF, Horton ES, Oken E. (2020). Dietary characteristics associated with plasma concentrations of per- and polyfluoroalkyl substances among adults with pre-diabetes: Cross-sectional results from the Diabetes Prevention Program Trial. Environ Int. 137:105217.
13. Dzierlenga MW, Keast DR, Longnecker MP. (2021). The concentration of several perfluoroalkyl acids in serum appears to be reduced by dietary fiber. Environ Int. 146:106292.