PFAS Forever Chemicals: The Cover-Up in Your Blood
How DuPont and 3M concealed evidence that PFAS chemicals contaminate virtually every human on Earth
What Are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a class of approximately 15,000 synthetic chemicals characterized by carbon-fluorine bonds — one of the strongest bonds in organic chemistry. This strength makes PFAS extraordinarily resistant to degradation. They do not break down in the environment and accumulate in living organisms, earning them the name “forever chemicals.” PFAS have been used since the 1940s in nonstick cookware (Teflon), waterproof clothing, food packaging, firefighting foam (AFFF), and hundreds of other consumer and industrial products.
What the Companies Knew
Internal documents produced in litigation reveal that DuPont and 3M — the two largest PFAS manufacturers — knew about the chemicals’ toxicity and environmental persistence decades before public disclosure.
3M’s own studies in the 1960s and 1970s showed that PFAS accumulated in the blood of production workers and in animals near manufacturing facilities. By the 1970s, 3M had documented liver damage, developmental problems, and immune suppression in animal studies. The company did not disclose these findings to regulators or the public.
DuPont’s internal records, revealed through litigation led by attorney Robert Bilott beginning in 1998, showed that the company had known since at least 1961 that PFOA (a key PFAS compound used in Teflon production) was toxic. By the 1980s, DuPont’s own medical staff had linked PFOA exposure at its Washington Works plant in Parkersburg, West Virginia, to birth defects among workers’ children. DuPont continued manufacturing and did not inform the affected community.
The Bilott Investigation
Robert Bilott, a corporate defense attorney at Taft Stettinius & Hollister, began investigating DuPont’s Parkersburg operations in 1998 after a farmer near the plant reported that his cattle were dying. Bilott’s investigation, which eventually spanned over two decades, uncovered DuPont’s internal documentation of PFOA toxicity. A community health study — the C8 Science Panel — conducted between 2005 and 2012, involving nearly 70,000 residents near the plant, found probable links between PFOA exposure and six diseases: kidney cancer, testicular cancer, thyroid disease, ulcerative colitis, high cholesterol, and pregnancy-induced hypertension.
PFAS in the General Population
PFAS are now detectable in the blood of approximately 98% of Americans tested. They have been found in drinking water supplies serving over 100 million people. Contamination is concentrated around military bases (where AFFF firefighting foam was used extensively), manufacturing sites, and wastewater treatment plants, but PFAS are effectively ubiquitous in the environment.
Settlements and Regulation
In June 2023, 3M agreed to a settlement of $10.3 billion to $12.5 billion to resolve claims from public water systems contaminated with PFAS. DuPont and its successor companies Chemours and Corteva agreed to a $1.185 billion settlement. Additional lawsuits involving personal injury, military base contamination, and firefighter exposure continue.
In April 2024, the EPA issued the first-ever national drinking water standards for PFAS, setting maximum contaminant levels of 4 parts per trillion for PFOA and PFOS. The standards require public water systems to monitor and reduce PFAS levels by 2029. Total settlement and remediation costs are projected to exceed $15 billion.
Research Verdict
| Assessment | CONFIRMED |
| Confidence | High |
| Summary | DuPont and 3M knew for decades that PFAS chemicals were toxic and environmentally persistent, concealed this knowledge from regulators and the public, and continued manufacturing them |