What Is Chloramine in Tap Water?

Chloramine is the other disinfectant in US tap water. If your utility uses it, it matters mostly when you pick a filter.

What is chloramine, and why do utilities use it?

According to the EPA, chloramines are most commonly formed when ammonia is added to chlorine, and they provide longer-lasting disinfection as water moves through the pipes. Utilities have used them since the 1930s, and more than one in five Americans now drinks chloraminated water. Some utilities switched to meet the rules on disinfection byproducts: the EPA’s Q&A says monochloramine is more chemically stable than chlorine and produces fewer of the regulated byproducts.

Is chloramine safe?

The EPA says water with chloramines that meets its standards is safe for drinking, cooking, bathing and other household uses. Its legal limit, the maximum residual disinfectant level, is 4.0 mg/L, the same as for chlorine (EPA).

Can a filter remove it?

Some drinking water filters are certified for chloramine reduction; check the listing for that exact claim. Shower filters aren’t: the only claim on NSF’s shower filter listings is free chlorine reduction. Our guide to shower filters explains what that means, and your utility can tell you which disinfectant it uses; its water quality report lists it against the MRDL.