1,2-Benzisothiazolin-3-one

1,2-Benzisothiazolin-3-one (CAS 2634-33-5), commonly abbreviated as BIT, is a heterocyclic biocide marketed under trade names including BIT-85, Proxel, and Proxil. It carries no assigned E-code and is registered under EC 220-120-9. It is also referenced in formulation contexts by the abbreviations MFR and IPX.

BIT functions by disrupting microbial cell membranes and inhibiting enzyme activity, making it effective as a preservative in water-based coatings, adhesives, and metalworking fluids. In personal care and textile processing applications, it controls bacterial and fungal growth in aqueous systems at low active concentrations, typically in the range of 100 to 500 ppm.

The compound is supplied as a yellow powder in neat form and is subject to REACH registration requirements within the EU. Procurement teams should verify SDS compliance and biocidal product authorisation under BPR (EU 528/2012) for the intended application category. HS code 29339900 applies for import and export classification.