PFAS are per- and polyfluoroalkyl substances, highly toxic synthetic chemicals that have been 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, fire-fighting foams, food packaging, and other products that resist grease, stains, and stains. 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 newborns.

Industry records show that 3M and DuPont, major manufacturers of PFAS, hid what they knew of the dangers for decades. Beginning in the mid-2000s, independent studies have linked exposure to very low levels of certain PFASs to cancer, birth defects, reproductive and immune system damage, high cholesterol, and obesity. .

Yet PFAS are still not federally regulated.

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 that DuPont begins purchasing from its rival four years later to prevent Teflon powder from clumping during production.

1950: A study on 3M mice reveals an accumulation of PFAS in the 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 stain removers.

1960: The Food and Drug Administration approves Teflon nonstick cookware.

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

1966: In collaboration with 3M, the US Navy obtains a patent for aqueous fire-fighting foam, a product containing PFAS. 3M sells it to firefighters in 5 gallon buckets.

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

1970: A company that bought 3M fire-fighting foam finds it kills fish, prompting a pilot study to halt.

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

1975: A University of Florida researcher asks 3M if Scotchgard and Teflon products are a 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 that PFOA and PFOS “should be considered toxic.” DuPont is concerned that PFOA could cause “toxic effects” among employees at its Teflon plant in West Virginia, but does not share the information outside of the company.

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

Early to mid-1990s: DuPont finds increased cancer rates among PFAS workers, three years after 3M discovered a similar trend among its workers.

1998: 3M scientist Richard Purdy tells his bosses that PFOS moves through the food chain. The company warns the United States Environmental Protection Agency for the first time that PFOS is accumulating in human blood.

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

2000: The US EPA is pressuring 3M to phase out Scotchgard and Teflon PFOS and PFOA chemicals, five months before DuPont settles a lawsuit that began exposing the secret history of PFAS.

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

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

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

2007: One study estimates that PFOA and PFOS are in the blood of over 98% of Americans.

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

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

2012: A landmark study of 70,000 people living near the DuPont 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 certain water systems, the US EPA found high levels of PFOA and PFOS in the drinking water of Freeport, a small industrial town west of Rockford. Neither federal nor state authorities are looking for the chemicals in the rest of Illinois.

2016: The US EPA issues a stricter health advisory for PFOA and PFOS in drinking water: 70 parts per trillion. The administration of President Barack Obama, however, does not regulate chemicals.

2017: After losing three personal injury lawsuits in federal court, DuPont is settling dozens more accusing the company of being responsible for PFOA-related health issues. DuPont pledges to pay $671 million to more than 3,500 injured people. Three years later, the company settles 100 more claims for $81 million.

2017: GenX, a Teflon PFAS that DuPont has sworn is safer than PFOA, is first detected in drinking water 100 miles downstream from the Fayetteville, North Carolina plant. 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 were detected in drinking water near one of the company’s manufacturing plants in Cottage Grove , a suburb of Minneapolis.

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

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

2021: President Joe Biden’s administration announces a “strategic roadmap” to address PFAS pollution nationwide. The Illinois EPA proposes limits for PFAS in groundwater and is committed to limiting 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: The US EPA is issuing exponentially stricter new health advisories for PFOA and PFOS, concluding after a review of the latest research that there is essentially no safe exposure level in drinking water. The agency is also releasing its first health advisories for Generation X and PFBS, chemicals that have replaced PFOA and PFOS in many products. None of the opinions are binding, but the Biden administration promises to announce legal standards later in 2022.

Sources: US Environmental Protection Agency, Illinois EPA, court records, Environmental Task Force, Tribune reports.