1,2-Benzisothiazolin-3-one
[CAS# 2634-33-5]

Identification

• Classification: Food additive >> Preservative
• Name: 1,2-Benzisothiazolin-3-one
• Synonyms: 1,2-Benzisothiazol-3(2H)-one; Benzisothiazolin-3-one; Proxan; Proxel; Proxel XL; Proxil
• Molecular Formula: C₇H₅NOS
• Molecular Weight: 151.18
• CAS Registry Number: 2634-33-5
• EC Number: 220-120-9
• SMILES: C1=CC=C2C(=C1)C(=O)NS2

Properties

• Density: 1.4±0.1 g/cm³, Calc.^*
• Melting point: 154-158 °C (Expl.)
• Index of Refraction: 1.661, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Risk Statements: H302-H315-H317-H318-H400-H410-H411
• Safety Statements: P261-P264-P264+P265-P270-P272-P273-P280-P301+P317-P302+P352-P305+P354+P338-P317-P321-P330-P332+P317-P333+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute toxicity	Acute Tox.	2	H330
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin sensitization	Skin Sens.	1A	H317
Acute toxicity	Acute Tox.	1	H330
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2	H318

• Transport Information: UN 3077

Discovery and Applications

1,2-Benzisothiazolin-3-one (BIT) is an organic compound with the molecular formula C7H5NOS. It is a colorless to pale yellow liquid that is primarily used as a biocide and preservative in various industrial applications. BIT belongs to a class of compounds known as isothiazolones, which are characterized by their ability to inhibit the growth of microorganisms.

The discovery of 1,2-benzisothiazolin-3-one can be traced to research conducted in the late 20th century when the search for effective and environmentally friendly biocides gained importance. BIT was developed as a broad-spectrum antimicrobial agent capable of inhibiting the growth of bacteria, fungi, and algae. It quickly became a valuable alternative to other more hazardous biocides, such as formaldehyde-releasing agents, in industrial formulations.

1,2-Benzisothiazolin-3-one is widely used as a preservative in aqueous formulations, including paints, coatings, adhesives, and personal care products. Its primary application is in water-based formulations, where it helps prevent microbial growth, particularly in products that are prone to contamination, such as cosmetics, household cleaners, and detergents. The compound is effective against a broad spectrum of microorganisms, including bacteria, yeasts, and molds, making it highly versatile in the preservation of various products.

In addition to its use in personal care and household products, BIT is commonly used in industrial applications such as cooling tower water treatment, oilfield chemicals, and in the paper and textile industries. In these industries, BIT serves as a preservative to prevent the growth of bacteria and fungi in industrial fluids and other aqueous systems. It is often incorporated into formulations for use in systems where microbial contamination could lead to issues such as foul odors, product degradation, or reduced system efficiency.

BIT has also been investigated for its role in preventing the growth of algae in water treatment systems, and it is commonly added to formulations for algae control in swimming pools and water reservoirs. The compound's efficacy in inhibiting microbial growth at low concentrations, combined with its relatively low toxicity compared to some other biocides, has made it a widely used agent in the formulation of preservatives for various industrial and consumer products.

In summary, 1,2-benzisothiazolin-3-one is a versatile and widely used biocide that serves as an effective preservative in a range of industrial and consumer products. Its discovery as a potent antimicrobial agent has led to its widespread use in the preservation of water-based formulations, and its ability to inhibit bacterial, fungal, and algal growth has made it an important compound in industries such as personal care, paints, coatings, and water treatment.

References

2024. Discovery of Highly Effective Antibacterial Agents Based on Chalcone-Benzisothiazolinone. Journal of Agricultural and Food Chemistry, 72(44).
DOI: 10.1021/acs.jafc.4c09234

2024. Effect-directed analysis of genotoxicants in food packaging. Analytical and Bioanalytical Chemistry, 416(29).
DOI: 10.1007/s00216-024-05632-y

2024. Dermal toxicity studies of 1,2-benzisothiazolin-3-one. Food and Chemical Toxicology, 182.
DOI: 10.1016/j.fct.2024.115054