Chloramine is a toxic gas (NH₂Cl) created by the combination of ammonia and sodium hypochlorite (bleach). It has been used as a poison gas. In commonly used in low concentrations as a disinfectant in municipal water systems as an alternative to chlorination.

Chloramine use by water purification plants is increasing. Chlorine is being phased out in favor of chloramine because chloramine is much more stable and won't dissipate from the water before it reaches consumers. There is also less tendency to form halomethanes such as carbon tetrachloride in the presence of organic materials. Halomethanes have been recognized as a health hazard. Furthermore, water treated with chloramine lacks the distinct chlorine odor of the gaseous treatment and so has improved taste.

Aquarium owners must remove the chloramine from their tap water because it is toxic to fish. Aging the water for a few days removes chlorine but not the more stable chloramine, which can be neutralised using products available at pet stores.

Home brewers use chemicals such as Sodium metabisulfite to remove Chloramine from brewing liquor as it cannot be removed by boiling, as is used with chlorine.

External links

• Chlorine and chloramines in the freshwater aquarium
• Chloramine in drinking water facts