Due to NDA, I can't talk about specifics, but a fab is basically a bunch of small chemical plants in the same (giant) room. There are all sorts of dangerous chemicals in use, but there are multiple layers of safety equipment and protocols to ensure their safe use. Because of how seriously they take safety, the most common injuries were things like ergonomic strain or tripping down stairs. Every stairwell has multiple "Keep one hand free for the rail" signs.

That being said, serious accidents have happened when employees violated procedures/protocols, failed to lock-out/tag-out, or defeated interlocks inappropriately. You can read about them in the press. For example: https://www.oregonlive.com/silicon-forest/2018/10/intel_sued...

Employees who fail to follow safety protocols rarely keep their jobs, even if there happened to be no injuries.

I've done lithography in research settings. To me, the chemistry is the scariest.

High voltages, high-power optics, vacuum systems, etc, all exist, too, but the risks associated with chemistry/process-gas accidents are perhaps the greatest.

As a teaser, HF is used throughout the industry -- it is spooky stuff (and awesome at getting things done).

The chemistry is easily the most dangerous aspect for humans and safety protocols have been developed to match. Chances of exposure at the tool-level are probably zero (i.e. on the factory floor you see pictures of). If you are working with bulk chemicals (i.e. one of the support floor(s) below the factory floor), chances are probably higher that you could run into some exposure.

I would say that it is an extremely safe occupation, having worked previously at a major semiconductor manufacturing facility for a few years. A lot of the staff virtually never enter the cleanroom. I personally only ever went in there 3-4 times. The automation is nearly absolute, so most of the effort is spent making sure the computers are doing the right thing. Sending humans into the cleanroom is directly in conflict with the objective of realizing low defect rates, because people are walking particulate factories.

Other than the nuclear fuel processing industry, the semiconductory industry is the only other place where you're likely to come across chlorine triflouride, which is the fun stuff that'll set concrete on fire.

https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa...

Semi-related, he kind of covers it in here: https://www.youtube.com/watch?v=NGFhc8R_uO4