Haloaldehydes

Organic compounds whose carbon chain molecules contain the C=O (carbonyl) functional group at the end of a carbon chain (aldehydes), with one or more hydrogen atoms substituted by halogens (chlorine, bromine, fluorine, and/or iodine). Chloral hydrate and chloroacetaldehyde are haloaldehydes. Although some toxicity data is available for chloral hydrate, little is known of the potential health effects of other haloaldehydes.

Source: GreenFacts

Haloaldehydes are found as water disinfectant byproducts in chlorinated water as a consequence of the reaction of chlorine with natural organic matter and bromide ions in the raw water supply (from lake, reservoirs, rivers etc).

Source: GreenFacts

Water Disinfectants