Trichloroisocyanuric acid is an organic compound with the formula (C3Cl3N3O3). It is used as an industrial disinfectant, bleaching agent and a reagent in organic synthesis. This white crystalline powder, which has a strong "chlorine odor," is sometimes sold in tablet or granule form for domestic and industrial use. Salts of trichloroisocyanuric acid are known as trichloroisocyanurates. Trichloroisocyanuric acid is prepared from cyanuric acid via a reaction with chlorine gas and sodium hydroxide.