The origin of these highly toxic man-made chemicals

PFAS are per- and polyfluoroalkyl substances, highly toxic man-made chemicals used in industrial and consumer products since the 1950s.

The chemicals have been added to nonstick cookware, water-repellent clothing, stain-resistant fabrics and carpets, cosmetics, firefighting foams, food packaging and other products that resist grease, oil and water.

PFAS persist in the environment and accumulate in people, animals and aquatic life. These “forever chemicals” are in the blood of nearly every American, including newborn babies.

Industry records show 3M and DuPont, the chief manufacturers of PFAS, hid what they knew about the dangers for decades. Beginning in the mid-2000s, independent studies linked exposure to very small concentrations of certain PFAS to cancer, birth defects, reproductive and immune system harm, high cholesterol and obesity.

Yet PFAS still aren’t regulated by the federal government.

1938: A DuPont scientist inadvertently discovers polytetrafluoroethylene, or PTFE. Eight years later, the company begins selling commercial products with PFTE under the Teflon brand.

1947: 3M begins mass producing PFOA, a PFAS chemical DuPont starts buying from its rival four years later to prevent Teflon powder from clumping during production.

1950: 3M mice study reveals PFAS build up in blood.

1953: A 3M chemist spills another PFAS called PFOS on a tennis shoe. The chemical repels oil and water, prompting the company to create the Scotchgard brand of anti-stain products.

1960: Food and Drug Administration approves Teflon nonstick cookware.

1961: DuPont confirms PFOA is toxic in animals and causes observable changes in organ functions.

1966: Working with 3M, the U.S. Navy secures a patent for aqueous firefighting foam, a PFAS-containing product. 3M sells it to fire departments in 5-gallon buckets.

1967: Food and Drug Administration approves Zonyl, a PFAS coating DuPont sells for food packaging.

1970: A company that purchased 3M’s firefighting foam finds it kills fish, prompting the abrupt halt of a pilot study.

1973: DuPont study documents liver damage from exposure to PFAS in food packaging.

1975: University of Florida researcher asks 3M whether Scotchgard and Teflon products are source of fluorinated chemicals detected in samples from New York and Texas blood banks. 3M executives “plead ignorance” but secretly confirm the findings.

1978: 3M concludes PFOA and PFOS “should be regarded as toxic.” DuPont worries PFOA might be causing ‘’toxic effects’’ among employees at its Teflon plant in West Virginia but does not share the information outside the company.

1980s: DuPont and 3M reassign female workers after children of Teflon plant employees are born with facial disfigurations and other birth defects. DuPont discovers high levels of the chemical in drinking water outside the Teflon plant. None of this is shared outside the company.

Early to mid-1990s: DuPont discovers increased rates of cancer among PFAS workers, three years after 3M found a similar pattern among its workers.

1998: 3M scientist Richard Purdy tells his bosses PFOS moves throughout the food chain. The company warns the U.S. Environmental Protection Agency for the first time that PFOS accumulates in human blood.

1999: Purdy quits 3M in protest, calling PFOS more damaging than banned PCBs.

2000: U.S. EPA pressures 3M to phase out the Scotchgard and Teflon chemicals PFOS and PFOA, five months before DuPont settles a lawsuit that began unraveling the secret history of PFAS.

2002: U.S. EPA concludes that cancerous tumors in rats exposed to PFOA “are relevant to humans.”

2004: DuPont settles a class-action lawsuit and agrees to finance a study of PFOA’s effects on people living near the company’s Teflon plant in Parkersburg, West Virginia.

2005-2006: DuPont fined $10.2 million and 3M $1.5 million for failing to report PFAS studies to U.S. EPA.

2007: Study estimates PFOA and PFOS are in the blood of more than 98% of Americans.

2009: During the last month of President George W. Bush’s administration, U.S. EPA announces “health advisory” limits of 400 parts per trillion for PFOA and 200 ppt for PFOS in drinking water. But the agency declines to regulate the chemicals.

2009: Chicago Department of Water Management finds PFOS in treated Lake Michigan water distributed to more than 5 million Illinoisans, shortly after testing commissioned by the Chicago Tribune first revealed that PFOA and PFOS contaminate local drinking water.

2012: Landmark study of 70,000 people living near DuPont’s Teflon plant links PFOA exposure to six diseases: testicular and kidney cancer, high cholesterol, ulcerative colitis, thyroid disease and pregnancy-induced hypertension.

2013-14: During a nationwide study of select water systems, U.S. EPA finds high levels of PFOA and PFOS in the drinking water of Freeport, a small industrial city west of Rockford. Neither federal nor state officials look for the chemicals throughout the rest of Illinois.

2016: U.S. EPA issues a more stringent health advisory for PFOA and PFOS in drinking water: 70 parts per trillion. President Barack Obama’s administration does not regulate the chemicals, though.

2017: After losing three personal injury lawsuits in federal court, DuPont settles dozens of others accusing the company of responsibility for PFOA-related health problems. DuPont agrees to pay $671 million to more than 3,500 people harmed. Three years later, the company settles 100 additional claims for $81 million.

2017: GenX, a Teflon PFAS that DuPont vowed was safer than PFOA, is detected for the first time in drinking water 100 miles downstream from the company’s Fayetteville, North Carolina, factory. The North Carolina State University researcher who found the chemical estimates at least 250,000 people are at risk.

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2018: 3M agrees to pay $850 million to settle a lawsuit filed by the state of Minnesota after high levels of PFAS are detected in drinking water near one of the company’s manufacturing plants in Cottage Grove, a Minneapolis suburb.

2019: PFAS contaminate drinking water or groundwater at nearly 400 military bases that used firefighting foam, the nonprofit Environmental Working Group finds. The number of bases with confirmed PFAS contamination jumps to 679 by July 2021.

2020: The Illinois EPA launches long-delayed statewide investigation of PFAS in drinking water.

2021: President Joe Biden’s administration announces a “strategic road map” to address PFAS pollution nationwide. Illinois EPA proposes PFAS limits in groundwater and vows to limit the chemicals in drinking water.

2022: Illinois Attorney General Kwame Raoul accuses 3M of failing to control PFAS pollution from a manufacturing plant on the Mississippi River upstream from the Quad Cities.

2022: U.S. EPA issues new, exponentially more stringent health advisories for PFOA and PFOS, concluding after a review of the latest research that there is essentially no safe level of exposure in drinking water. The agency also issues its first health advisories for Gen X and PFBS, chemicals that replaced PFOA and PFOS in many products. None of the advisories are enforceable, but the Biden administration promises to announce legal standards later in 2022.

Sources: U.S. Environmental Protection Agency, Illinois EPA, court records, Environmental Working Group, Tribune reporting.