- The primary gaseous agents used were chlorine, phosgene, a combination of the two, and mustard gas.
- Now obviously all of that wasn't mustard, a lot of the deaths were actually due to phosgene and chlorine.
- However, its immediate precursor compound, thiodiglycol, is used industrially, although in quantities that don't come anywhere near chlorine or phosgene.
- New agents, notably phosgene (an asphyxiating agent) and mustard (a blister agent called a vesicant), had been developed and used.
- Greenpeace found that perc breaks down into the toxic byproducts phosgene, vinyl chloride, carbon tetrachloride and trichloroacetic acid.