Good article, lots of specifics as to what the accusations against TSMC are. Also, it appears there is a paper trail to back them up:
Earlier this month, after multiple health and safety complaints were sent to the state over the past year, TSMC and the state of Arizona signed a workplace-safety agreement. Both sides agreed to subject the company to higher safety standards than required at the federal level, including closer oversight and increased training and safety visits.
https://www.bbc.com/news/technology-65789916
Apparently it was a story told by an Air Force colonel at an aeronautics conference, who later retracted it.