Chlorine dioxide (ClO2)
Distribution waters - Disinfection

In the presence of ammonia, chlorine dioxide does not form chloramines.

In the presence of organic matter, it forms few haloforms. It oxidizes phenols to quinones, which do not give rise to off-flavours. It can destroy complexes formed with iron or manganese and humic substances, and subsequently destroy humic acids.

However, water treated with ClO ₂ contains chlorites $\left({\text{ClO}}_2^{-}\right)$...