There are several types of bleach, but the use of chlorine bleach is likely what you are inquiring about.
Here is a quote from the Housekeeping Channel at: www.housekeepingchannel.com
"Use bleach only in well-ventilated areas. Take a break in the fresh air at the first sign of any irritation from chloride vapors; wear eye protection and a face mask if necessary.
Those fumes hint strongly that chlorine bleach is a reactive agent. Bleach reacts badly with many other strong chemicals. Combining liquid bleach with ammonia, drain cleaners, automatic dishwasher detergent or other strong acids or alkalis may set off chemical reactions that release toxic fumes or produce hazardous solutions that can burn skin and eyes or harm the environment.
Mix bleach with water, mild soap or laundry detergent only. If you don''t know all of the ingredients used in a cleaning product, it''s safest to avoid mixing chlorine bleach with it."