Chlorinated solvents are extremely dangerous, phosgene gas is what the Nazi's used in WWII as a nerve agent. FWIW, R22, R12, R500 and several other refrigerants are chlorinated and pose the same dangers.
The best solvent there is for cleaning metal before welding and so on is denatured alcohol, it is not as effective and takes longer, but burns clean and cold and does not flash.
Never use acetone, it literally explodes when it flashes, also, when welding gas or diesel tanks, be really really careful. Use nitrogen (dry) or argon to displace any fumes, and do it outside.
GT