"Hansen didn’t want to share her results until she was certain that they were correct, so she and her team spent several weeks analyzing more blood...
Her managers were less concerned about PFOS than about the chance that she was wrong."
"In 1979, an internal company report deemed PFOS “certainly more toxic than anticipated”
Hodge urged [3M] to study whether the company’s fluorochemicals caused reproductive issues or cancer...& he added, “If the levels are high & widespread & the half-life is long, we could have a serious problem."
https://www.propublica.org/article/3m-forever-chemicals-pfas-pfos-inside-story