How 3M executives convinced a scientist the forever chemicals she found in human blood were safe
ProPublica reports: Kris Hansen had worked as a chemist at the 3M Corporation for about a year when her boss, an affable senior scientist named Jim Johnson, gave her a strange assignment. 3M had invented Scotch Tape and Post-it notes; it sold everything from sandpaper to kitchen sponges. But on this day, in 1997, Johnson wanted Hansen to test human blood for chemical contamination. Several of 3M’s most successful products contained man-made compounds called fluorochemicals. In a spray called Scotchgard,…