glumshoe:

Mixing bleach and vinegar produces toxic chlorine gas. 

Mixing bleach and ammonia produces toxic chloramine vapor.

Obviously, don’t mix any cleaning products when doing housekeeping, unless you have very carefully read the warning labels and know exactly how they’ll react. 

But also…. pee contains ammonia. Urea in fresh pee breaks down to create more ammonia, so old, stale piss has a higher concentration of ammonia and will have a nastier reaction with bleach.