Chlorine is a heavier-than-air yellowish-green gas with an irritating odor. It is used widely in chemical manufacturing, in bleaching, and (as hypochlorite) in swimming pool disinfectants and cleaning agents. Hypochlorite is an aqueous solution produced by the reaction of chlorine gas with water; most household bleach solutions contain 3–5% hypochlorite, and swimming pool disinfectants and industrial-strength cleaners may contain up to 20% hypochlorite. The addition of acid to hypochlorite solution may release chlorine gas. The addition of ammonia to hypochlorite solution may release chloramine, a gas with toxic properties similar to those of chlorine.