I'm fairly new to the site but i run my own welding company, mostly stainless tube for the drinks industry,
one article which i make all my guys read is this one, http://www.brewracingframes.com/id75.htm
Its about the dangers of toluene and other chlorinated hydrocarbons, sobering stuff, it's probably been posted before, if so then thats fine but if you havent read it then have a quick look, it might save you a lot of grief.
Toluene is not chlorinated. It's an aromatic hydrocarbon: methylbenzene. http://en.wikipedia.org/wiki/Toluene