1,2-Benzisothiazolin-3-one (BIT) is a near-white to pale yellow crystalline powder at room temperature, although it is commonly used in industrial applications in liquid forms such as solutions or dispersions. It is slightly soluble in water but readily soluble in alkaline solutions and certain organic solvents. As a highly effective, broad-spectrum industrial biocide and preservative, BIT exhibits stable chemical properties and remains active across both acidic and alkaline environments. However, prolonged exposure to strongly alkaline conditions (pH > 9.5) may lead to gradual hydrolysis. Its core biocidal mechanism involves contacting and penetrating microbial cell membranes, where it releases active molecules that disrupt intracellular enzyme metabolism, thereby effectively killing and inhibiting bacteria, fungi, and algae. Owing to its strong efficacy, long-lasting action, low volatility, and stability across a wide pH range, BIT is primarily used as a preservative in industrial systems. It is widely applied in water-based coatings, adhesives, metalworking fluids, papermaking processes, oilfield water injection, and industrial circulating cooling water systems. It is particularly suitable for formulations that require strict control of skin irritation or demand long-term preservation stability. Compared to some other isothiazolinone-based biocides with higher sensitization potential, BIT presents a lower risk of skin sensitization.