Benzisothiazolinone is an antimicrobial and preservative used in a wide variety of applications, such as cleaning and building products. It may be in the form of a white to yellow powder or liquid.
- Synonyms: BIT; 1,2-Benzisothiazol-3(2H)-one; 1,2-Benzoisothiazolin-3-one; Benzoisothiazolin-3-one
- Trade Names: IPX, Proxan, Proxel, Proxel PL, Nipacide BIT, Mergal BIT
- Chemical Formula: C7H5NOS (See the Chemistry Structures Index for more information.)
Benzisothiazolinone is used in several cleaning products, including green cleaning ones, such as laundry detergents, air fresheners, fabric softeners, stain removers, dish detergents, stainless steel cleaners, and more. It is used at a rate of 0.10% to 0.30% (by weight) when added to laundry and household cleaning products according to the EPA in the 2005 document, Registration Eligibility Decision (RED) for Benzisothiazoline-3-one. Also, it is important to point out that it is often used in many cleaning products in conjunction with methylisothiazolinone, a synthetic preservative with some health concerns.
In addition to cleaning products, benzisothiazolinone has a dizzying number of other uses. It may be found in flea and tick treatments, paints, stains, car care products, textile solutions, metalworking fluids, oil recovery fluids, leather processing chemicals, pesticides, paper mill systems, and building products, such as adhesives, caulks, sealants, grouts, spackles, and wallboards. Also, it is commonly used in personal care products, such as sunscreens and liquid hand soaps, and as an inert ingredient on crops, such as blueberries, strawberries, tomatoes, spinach, lettuce, and more.
Product Brands Containing Benzisothiazolinone
To see if certain products contain benzisothiazolinone, try searching the U.S. Department of Health and Human Services Household Products Database, the Environmental Working Group's (EWG) Guide to Healthy Cleaning, the Good Guide, or the EWG's Skin Deep Cosmetic Database.
When benzisothiazolinone is used in personal care preparations or applications that come into contact with food, it is monitored by the U.S. Food and Drug Administration (FDA). For other uses, such as pesticides and cleaning products, it is monitored by the EPA.
Health & Safety
In 2005, benzisothiazolinone underwent a review process by the EPA to determine its reregistration eligibility for use in a range of products and applications. After considering the overall information on its toxicity, uses, and environmental effects, the EPA concluded that it posed no harm to the population. However, that doesn't mean no health effects were found at all.
In the report, the EPA did note that it can be irritating to the skin and eyes and act as a dermal sensitizer. So, considering that it can be used in laundry products and in personal care products that come into contact with the skin, this is something to consider.
Also, the EPA did find that the amount that was being used in flea and tick products was a concern for children, so it specified the allowable amount in those products.
This chemical quickly biodegrades and there is "minimal environmental exposure" according to the EPA in its 2005 review of the chemical. However, the EPA also notes that there is evidence for benzisothiazolinone being toxic to aquatic life when it is used in oil-recovery fluids. So clearly, some applications for this chemical really shouldn't be allowed.
There are plenty of preservatives on the market that don't have any known issues, so seek out green products that don't use benzisothiazolinone as a preservative or antimicrobial if you're concerned. Carefully read ingredient labels and product reviews to help you know what you're getting.