Bromide is a salt found in seawater and some groundwater. It can form harmful byproducts during water treatment. Industrial sources include oil/gas production and flame retardants.

Bromide occurs naturally in seawater and some groundwater sources. It's also released through industrial processes like oil and gas extraction, and the production of flame retardants. While bromide itself is not typically harmful, it can react with chlorine during water treatment to form disinfection byproducts, which may pose health risks. Water utilities monitor bromide levels using ion chromatography or colorimetric methods to assess the potential for byproduct formation and adjust treatment processes accordingly.