Observation of an individual with immediate-type reaction following exaggerated dermal exposure to hypochlorite-containing cleaning products prompted review of similar hypersensitivity reactions attributed to hypochlorite or other highly reactive chemicals. This review confirms isolated incidences of hypochlorite sensitivity of the delayed type (allergic contact dermatitis), as well as immediate-type reactions from inhalation or topical challenge of sensitized individuals. We conclude that it is possible that excessive and prolonged exposure to hypochlorite may in some cases result in irritation and damage to the skin. This potentially gives rise to altered proteins which in rare cases may cause hypersensitivity. This reaction is common to other reactive small molecules with a strong irritant action.