When it is mixed with ammonia, it can create chloramine
gas, another toxic substance. Short-term
exposure to chloramine
gas may cause mild asthmatic symptoms or more serious respiratory problems. It can even form a toxic gas when hyper-chlorinated by hot water.
In the environment, sodium hypochlorite is acutely toxic to fish. The chlorine in bleach can also bind with organic material in the marine environment to form organochlorines, toxic compounds that can persist in the environment.