If you are talking about mixing bleach with ammonia, I have personal experience with this and "painful" is an understatement.
And no, I wasn't trying to ctb. I was helping a friend who owned a cleaning business and cleaning a trailer that a man had lived in with several parrots. He kept the birds on perches (he didn't believe in caging. Said it was cruel. I don't necessarily disagree but believe that your birds do need to be taught to cage -- like dogs and cats should be taught to crate -- for their own safety.) Anyway, I digress --
This guy kept a layer of cedar chips on the linoleum that was the flooring in the kitchen/dining room and swept and mopped pretty infrequently from what I could tell. ANYWAY



bird poo has a pretty high ammonia level. I swept the floor, mopped with water and Pine-sol and let it dry. Then I got the bright idea that bleach would clean up any remaining germs nicely.
Yeah. It's a good thing it was summer and I had all the windows and doors open. The second that bleach hit the floor the traces of ammonia still left on the linoleum it produced chloramine gas. I only took one breath of it but that was more than enough. Good grief that shit burns! I was really REALLY lucky. No lasting effects but to this day there is no bleach or ammonia in my house. Can't stand the smell of either one of them.