Perfluorooctanoic acid (PFOA)

PFOA has been manufactured since the 1940s and was used by 3M (as Scotchgard) and DuPont (as a processing aid for Teflon) for decades [1]. Internal documents revealed in litigation show that both companies knew PFOA was building up in worker blood and causing health effects as early as the 1960s and suppressed the information from regulators. The contamination story was largely hidden from the public until attorney Rob Bilott — inspired by a West Virginia farmer whose cattle were dying near a DuPont plant — pursued decades of litigation that exposed the full scope of PFOA contamination of the drinking water serving Parkersburg, West Virginia and Lubeck, WV. The resulting health study (the C8 Health Project) on 70,000 residents provided definitive evidence of PFOA's link to kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, high cholesterol, and pregnancy-induced hypertension [2]. PFOA has largely been phased out of US manufacturing since 2006, but its replacement chemicals (PFAS) raise similar concerns, and PFOA contamination from decades of firefighting foam (AFFF) use at military bases remains a national crisis [3].

Drinking water contaminated by industrial discharges, AFFF firefighting foam at military bases and airports, and chemical manufacturing facilities is the most significant high-concentration exposure pathway [1]. More than 2,800 locations in the US have documented PFAS contamination in drinking water, many from military bases. Food packaging is a secondary route: grease-resistant food packaging, microwave popcorn bags, pizza boxes, and fast-food wrappers historically used PFOA-based coatings that migrate into food, particularly fatty hot foods [2]. Non-stick cookware made with older PTFE coatings and related chemicals is a source when overheated (above 500°F). Stain-resistant carpet and fabric treatments (Scotchgard) release PFOA and related PFAS through dust and off-gassing. House dust accumulates PFAS compounds and is a significant exposure route for young children who play on floors [3].

PFOA's defining characteristic is its extreme persistence: its half-life in the human body is approximately 3.5 years, meaning what you absorb accumulates for a lifetime [1]. The C8 Health Project established probable links (defined as a greater than 50% probability of causation by independent scientists) between PFOA exposure and six diseases: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, hypercholesterolemia (elevated cholesterol), and pregnancy-induced hypertension [2]. PFOA disrupts lipid metabolism (causing elevated cholesterol), suppresses the immune system (reducing vaccine efficacy in children), acts as an endocrine disruptor affecting thyroid and sex hormones, and impairs placental function during pregnancy. In 2024, the EPA set a maximum contaminant level for PFOA in drinking water at 4 parts per trillion — representing a recognition that previous standards were far too permissive [3].

People who drink water from municipal systems or private wells contaminated by PFAS from nearby military bases, airports, industrial facilities, or wastewater treatment plants face the highest exposures [1]. The EWG maintains an interactive PFAS contamination map. Workers at fluorochemical manufacturing facilities and people who lived in communities near them (Parkersburg, WV; Cottage Grove, MN; Decatur, AL) carry the highest historical body burdens [2]. Infants and young children are at elevated risk — PFOA transfers through breast milk, maternal blood, and placenta, and children's smaller bodies concentrate exposures more. People who regularly use stain-resistant treated carpeting or frequently consume fast food and microwave popcorn have measurable but lower dietary exposures [3].

Check EWG's Tap Water Database or your water utility's annual quality report for PFAS levels [1]. If your water tests above the new 4 ppt EPA limit for PFOA, install a reverse-osmosis filter (certified to NSF/ANSI 58) or a certified activated carbon block filter for drinking and cooking water. Do not microwave popcorn in the bag; use a dedicated popcorn maker or glass bowl instead [2]. Reduce use of fast food and food in greasy paper packaging. When shopping for new cookware, PTFE-coated non-stick pans used at normal temperatures are no longer made with PFOA, but cast iron and stainless alternatives eliminate the question entirely. Remove stain-resistant carpet treatments from your home — vacuum frequently with a HEPA filter to reduce PFAS-containing house dust [3]. Review EWG's guide to PFAS-free food packaging options for food storage.