Isocyanates are contact poisons. They don't have to be inhaled; they can penetrate skin. An occasional exposure isn't going to cause a hobbyist to keel over in his tracks, but all-day, every day exposure to isocyanates by a professional painter can cause some pretty nasty side effects. One of the worst is the sensation that bugs are crawling all over your skin, due to the cyanide damaging nerve endings just under the skin. The creepy-crawly feeling never really goes away. A filtered-air "shoot suit" that covers all exposed skin and draws its air supply from outside the paint booth is the safest way to shoot those paints. High-gloss hardeners used in basecoat/clearcoat paint systems also contain isocyanates.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!