The Intercept has obtained evidence that chemical conglomerate 3M knew about the health dangers of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) since the 1970s. These components were in thousands of everyday products, from water-repelling clothes to Teflon-coated non-stick pans, and they accumulate in your blood causing cancer, damaging your immune system, injuring your liver, spleen, bone marrow, and increasing cholesterol and triglycerides levels putting you at risk of heart attacks. Fun stuff.

These fluorochemicals were the basis for the company’s success, going from a small business called the Minnesota Mining and Manufacturing Company to a $120 billion conglomerate. The company used the discoveries from the Manhattan Project–which used fluorine to distill the uranium for the first atom bomb that dropped over Hiroshima–to develop a magic fluorocarbon fluid called PFOA. Dupont used PFOA to create Teflon, a coating used by hundreds of companies to manufacture miraculous–and toxic–non-stick cookware.

As The Intercept’s Sharon Lerner reports, University of Florida researcher Warren Guy found complex fluorine molecules in his own blood in 1975. He published the results and alerted 3M, asking the company if the molecules may be PFOA or PFOS coming from Teflon or Scotchgard water repellent, as he knew these materials had the same type of molecules. 3M told him they had no clue but the company scientists conducted an investigation and found out that the molecule Guy found in his blood was indeed 3M’s wonder molecule. Then, in a new internal investigation in 1976, company scientists found out that workers at 3M’s Cottage Grove PFOA plant in Minnesota had it in their blood, at concentrations 1,000 times higher than normal. By 1978, Lerner continues, 3M had concluded that PFOA and PFOS “should be regarded as toxic” in another internal report. And in 1979, 3M knew that people all over the United States had this crap in their veins thanks to an analysis of samples from Red Cross blood donors.

Did the company stop selling it then? No. 3M kept selling the compound to Dupont and other companies even after Rich Purdy, one of its environmental scientists, found out that the toxic component was everywhere in the food chain, from fish to humans. He voiced the alarm again inside the company, asking it to run more tests to see how far the poisoning went. But 3M management and the legal team ignored him: “I’m not sure there is a need to support or refute the hypothesis within any particular time frame,” a 3M attorney named Thomas DiPasquale wrote to his colleagues in the company’s corporate division in a 1999 email. As a result of these findings, the state of Minnesota sued 3M in 2005 and 2010.

In Europe, PFOS has been banned since 2008 and PFOA will be totally prohibited by 2020, although right now it’s hard to find a pan that uses Teflon in the old continent. In the United States, PFOA was banned in 2014. But it took four decades to get there as a result of litigation and EPA investigations. All that time, the company that made this knew about its toxicity and kept selling it. Go read the entire report by Lerner. It’s as infuriating as it is fascinating.