Mixing bleach and ammonia produces toxic gases called chloramines that can damage the upper respiratory tract and irritate the eyes, throat and nose. Symptoms include coughing, shortness of breath, watery eyes and nausea. Prolonged exposure to chloramines in an enclosed space can cause death, particularly if a person has any pre-existing respiratory conditions.
Bleach and ammonia each contain powerful chemicals that can prove toxic unless handled correctly. Bleach contains chlorine, a toxic element fatal in sufficient concentrations. Many other household cleaners use the chemical chlorine, including laundry detergent, toilet-bowl cleaner and dish-washing liquid. Combining any of these with ammonia-based cleaning products releases chloramines. Read the contents of a product carefully before use and note whether it contains bleach, chlorine or sodium hypochlorite. In addition to ammonia, bleach reacts with acids such as vinegar, releasing chlorine gas.
According to About.com, chloramine vapor is also toxic. In the event of a surplus of ammonia, this mixture has the potential to form an even more volatile compound called liquid hydrazine. This reaction is strongly exothermic, which raises the possibility that the liquid hydrazine will boil and spray creating its own hazards to people nearby. Sometimes, the liquid hydrazine is produced at such a high level of purity that it explodes. It follows that creating a mixture of ammonia and bleach is hazardous in the extreme and should be avoided, especially by non-chemists.
Household products use ammonium hydroxide dissolved in water for laundry use. Most glass- and porcelain-cleaning products contain ammonia because it cuts grease and cleans without leaving streaks. While ammonia can irritate, it generally isn't fatal. The level of toxicity depends on the quantities used.
While bleach and ammonia products provide benefits, their potential toxicity demands careful handling. Normal safety precautions, such as using rubber gloves, wearing eye protection and proper ventilation reduce the risk of possible injury.