3M Buried Early PFOS Toxicity

Internal 3M studies from the 1970s found PFOS harmed rat livers and killed monkeys at relatively low daily doses, yet the company kept results confidential and omitted outside toxicologists’ warnings from official notes. In 1997, a 3M chemist confirmed PFOS showed up in American Red Cross blood samples—meaning ordinary people were already contaminated—while managers questioned her methods instead of acting. — This strengthens the case for aggressive PFAS regulation, disclosure mandates, and corporate liability by showing early, concealed knowledge of harm and widespread exposure.