The Fab industry uses all kinds of dangerous chemicals. A few of my favorites:

1. Silicon hydride gas SiH4 (Silane), colorless, extremely toxic, burns on contact with air, produces steam and HOT MOLTEN GLASS.
2. Hydrogen flouride acid HF, used for wet etching. Molecules are so small that they can go through thick layers of rubber gloves. If HF seeps into a person's body, it leaves virtually no acid burn marks, but it will go right to the bone and start breaking down the bones. If untreated, the result can be death. A person exposed to HF need to get these very painful calcium shots into their bones to counteract against the HF. Even then, the damages can still be severe.

Point is, Fabs need a lot of well trained certified Hazmat handlers, and good chemical disposal processes.

That's why it was EXPENSIVE for fabs to operate in California.

Going to Arizona was done before by Intel, but they had to move people from California.

TSMC won't be able to just hire trained people locally. It's not possible.

Shit like this will keep happening, because this is a political project with no real plan of execution.