Benzisothiazolinone

Benzisothiazolinone has a microbicide and a fungicide mode of action. It is widely used as a preservative, for example in:

• emulsion paints, caulks, varnishes, adhesives, inks, and photographic processing solutions
• home cleaning and car care products; laundry detergents, stain removers and fabric softeners;
• industrial settings, for example in textile spin-finish solutions, leather processing solutions, preservation of fresh animal hides and skins
• agriculture in pesticide formulations
• gas and oil drilling in muds and packer fluids preservation.U.S. Environmental Protection Agency. September 29, 2005 [http://www.epa.gov/pesticides/reregistration/REDs/benzisothiazolin_red.pdf EPA Reregistration Decision]{{rp|iv}}

In paints, it is commonly used alone or as a mixture with methylisothiazolinone. Typical concentrations in products are 200–400 ppm depending on the application area and the combination with other biocides. According to a study in Switzerland, 19% of the paints, varnishes and coatings contained BIT in 2000. The fraction in adhesives, sealants, plasters and fillers was shown at that time as 25%.{{cite journal | author = Reinhard | display-authors = etal | year = 2001 | title = Preservation of products with MCI/MI in Switzerland | journal = Contact Dermatitis | volume = 45 | issue = 5| pages = 257–64 | pmid = 11722483 | doi = 10.1034/j.1600-0536.2001.450501.x | s2cid = 21296570 }} A later study in 2014 shows a dramatic rise in usage, to 95.8% of house paints.{{cite journal| pmid=25510184 | doi=10.1111/cod.12322 | volume=72 | issue=3 | title=Methylisothiazolinone and benzisothiazolinone are widely used in paint: a multicentre study of paints from five European countries | year=2015 | journal=Contact Dermatitis | pages=127–38 | author=Schwensen, J.F.; Lundov, M. D.; Bossi, R.; Banerjee, P.; Giménez-Arnau, E.; Lepoittevin, J. P.; Lidén, C.; Uter, W.; Yazar, K.; White, I. R.; Johansen, J.D.| s2cid=9651179 }}

Home cleaning and other care products that are high in water are easily contaminated by microorganisms, so isothiazolinones are often used as a preservative in these products because they are good at combatting a broad array of bacteria, fungi, and yeasts.

A Swiss investigation found that BIT is used in concentrations between 50 and 500 ppm in tattooing ink.{{Cite journal|last1=Garcia-Hidalgo|first1=Elena|last2=Sottas|first2=Virginie|last3=von Goetz|first3=Natalie|last4=Hauri|first4=Urs|last5=Bogdal|first5=Christian|last6=Hungerbühler|first6=Konrad|date=2017|title=Occurrence and concentrations of isothiazolinones in detergents and cosmetics in Switzerland|journal=Contact Dermatitis|volume=76|issue=2|pages=96–106|doi=10.1111/cod.12700|pmid=27862003 |s2cid=3918533 |doi-access=free}} According to regulations in the EU and Switzerland, BIT cannot be used in cosmetics. However, it is allowed in the United States and Canada.

Given sufficient dose and duration, dermal exposure can produce skin sensitization and allergic contact dermatitis,[https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+8271 ToxNet 1,2-Benzisothiazoline-3-one] and is classified as an irritant for skin and eyes. BIT's low molar mass allows for it to penetrate the epidermis and then react with the skin macromolecules, which causes the irritation. Benzisothiazolinone has also been linked with Systemic Contact Dermatitis via airborne contact.{{cite journal| author = Diljit Kaur-Knudsen, Torkil Menné, Berit Christina Carlsen| year = 2012| title = Systemic Allergic Dermatitis Following Airborne Exposure to 1,2-Benzisothiazolin-3-one| journal = Contact Dermatitis| volume = 67| issue = 5| pages = 310–312| doi = 10.1111/j.1600-0536.2012.02117.x| pmid = 23039006| s2cid = 35041455}}

In 2012, the Scientific Committee on Consumer Safety in Europe found BIT's "sensitising potential is of concern...Sensitisation from related isothiazolinones is an important problem in consumers. This has

occurred because there has been consumer exposure before safe levels of exposure relevant to sensitisation have been established. Benzisothiazolinone is a skin sensitiser in animal models with potency similar to methylisothiazolinone. Methylisothiazolinone, at 100 ppm (0.01%) in cosmetic products is causing contact allergy and allergic contact dermatitis in the consumer. Benzisothiazolinone is known to be a sensitiser in man and has induced sensitisation at circa 20 ppm in gloves."[http://ec.europa.eu/health/scientific_committees/consumer_safety/docs/sccs_o_099.pdf Scientific Committee on Consumer Safety (SCCS) Opinion on Benzisothiazolinone]

The opinion further states: "There is no information on what may be safe levels of exposure to benzisothiazolinone in cosmetic products from the point of view of sensitisation. Until safe levels of exposure have been established, the use of benzisothiazolinone in cosmetic products as a preservative or for other functions cannot be considered safe in relation to sensitisation."

Later, in 2013, researchers published a study that set out to derive the highest concentration of BIT in certain consumer products that would result in exposures below the No Expected Sensitization Induction Level (NESIL); that is, where normal use would yield a dose below the level at which skin sensitization might occur. The products under consideration were sunscreen, laundry detergent, dish soap, and spray cleaner; by way of calculation they derived BIT NESILs of 0.0075%, 0.035%, 0.035%, and 0.021%, respectively. They then performed a pilot examination via bulk sample analysis of one representative product from each category labelled as containing BIT. Their findings showed all BIT concentrations well below the derived NESIL, with 0.0009% and 0.0027% for sunscreen and dish soap, respectively, and no detection in the laundry detergent and spray cleaner products, meaning the concentration was at or below the limit of detection of 0.0006%.{{cite journal| pmid=23429043 | doi=10.1016/j.fct.2013.02.006 | volume=56 | title=Estimation of the Safe Use Concentrations of the Preservative 1,2-Benzisothiazolin-3-one (BIT) in Consumer Cleaning Products and Sunscreens | year=2013 | journal=Food Chem. Toxicol. | pages=60–6 | author=Novick, R.M.; Nelson, M.L.; Unice, K. M.; Keenan, J. J.; Paustenbach; D. J.}}

{{reflist}}

• Wilfried Paulus: Directory of Microbicides for the Protection of Materials and Processes. Springer Netherland, Berlin 2006, {{ISBN|1-4020-4861-0}}.

• {{Commons-inline}}

Category:Preservatives