For the maximum safety when using catalyzed paints (paint with hardener added separately) you should be using an air feed or positive pressure mask.
Years ago, I worked with a painting contractor who sprayed an interior commercial building roof with a two-part epoxy paint. He used a cartridge respirator. Thirty-six hours later he was dead of epoxy poisoning. Once a catalyzed paint's vapors have saturated your bloodstream, they cannot be made non-poisonous. The reaction to this inside the body is to cause swelling of internal organs, very ofter the heart. Such reactions are often mistakenly diagnosed as heart attacks.
Take my advice and don't play around with catalyzed paints such as auto paint (PPG, Imron, etc) without good breathing apparatus. I have two friends who own body shops and both of them use positive pressure masks, which supply clean outside air to them while painting.

Regards,
Al