Bleach reacts with organic matter to produce heat, but far less than caustic cleaners. More critically, bleach can react with other cleaning agents left in the drain (especially ammonia or acids) to produce toxic chloramine or chlorine gas. Additionally, bleach does not dissolve inorganic debris (mineral scale, sand), which often forms the core of a clog.
NaOCl decomposes in water to form hypochlorous acid (HOCl) and oxygen radicals: [ \textNaOCl + \textH_2\textO \rightarrow \textHOCl + \textNaOH ] These species attack organic molecules by breaking carbon-carbon and carbon-hydrogen bonds, converting complex polymers into smaller, more soluble fragments (e.g., carboxylic acids, alcohols).
