Benzoisothiazol-3-one is an organic heterobicyclic compound based on a fused1,2-thiazoleandbenzenebicyclic ring skeleton, with the S atom positioned adjacent to one of the positions of ring fusion. It has a role as a disinfectant, a platelet aggregation inhibitor, an environmental contaminant, a xenobiotic, a drug allergen and a sensitiser. It is an organonitrogen heterocyclic compound and an organic heterobicyclic compound.