Household bleach is 5% sodium hypochlorite. Mix it with ammonia and mono- and di-chloramines are formed. These nasty fellows will cause lovely symptoms such as respiratory tract irritation, tearing, and nausea. To make things better, add water to get hydrochloric acid and nascent oxygen- also known as chlorine gas, the chemical weapon of choice of Nazi Germany in World War II- for the added bonus of drowning in your own fluids!