There's plenty of things to be aware of here with chemicals. Heck even the paint on our trucks is a carcinogen if ground/sanded/exc. But one thing people might not think of is all the welding we do here. It's nice to clean up metal surfaces before welding to ensure a good weld with no flaws. I've done this myself before I knew about it, but you should NEVER use brake parts cleaner to clean off surfaces before welding. Welding produces UV radiation and intense heat. The chlorines, dichloromethane, and trichloroethane found in many of these can have a reaction and produce phosgene.
A little history lesson. Phosgene was used in WWI for some of the first chemical warfare. It produces a odor that smells something like fresh cut hay. But if you're able to tell this, it may be too late. It only takes 0.4 ppm for humans to detect the odor. About 4 times the safe level.
Here's a blurb about it from the CDC:
http://emergency.cdc.gov/agent/phosgene/basics/facts.asp
The problem is, it's very slow to effect the body, but the effects can be long term or death if one doesn't take care. And with all the odors from welding to start with, it's easy to not even know you've been poisoned.
