Isothiazolinone

Isothiazolinones are heterocyclic organic compounds, which occupy an important position within the biocides. The basic substance of the hydrocarbon group, isothiazolinone is a compound, in a five-membered ring is a cyclopentene sulfur and a nitrogen atom and contains one keto group ( Thiaazocyclopentenon ). Five isothiazolinone derivatives are used in significant quantities:

• Methylisothiazolinone (MIT, MI)
• Chloromethylisothiazolinone ( CMIT, CMI)
• Benzisothiazolinone (BIT )
• Octylisothiazolinone (OIT, OI)
• Dichloroctylisothiazolinon ( DCOIT, DCOI )

In addition, Butylbenzisothiazolinon ( BBIT ), but which plays a subordinate role exists.

Use

Isothiazolinones are used as a preservative against microorganisms ( bacteria, fungi) in aqueous dispersions, emulsions and solutions. Due to its bactericidal and fungicidal action to protect, for example, cleaning agents, paints, varnishes and adhesives prior to microbial decomposition. Other areas of application of isothiazolinones are paper-making, where they are used for slime control, cooling and process water and the antimicrobial finishing of textiles; you can find further also as a wood preservative use.

Are often used in emulsion paints of the mixtures CMIT / MIT and MIT / BIT. For the award of the Blue Angel maximum values ​​for CMIT / MIT may not be exceeded by 50 ppm and for MIT / BIT of 200 ppm.

Previously, the isothiazolinones were also very commonly used for shower gel, shampoo and cosmetics; because of their effect as contact allergens and a now introduced mandatory labeling is the use there in Germany declined sharply.

Biological Significance

Isothiazolinones have addition to the desired effect, the killing or controlling the growth of microorganisms and undesirable effects. So they have a high aquatic toxicity, and some isothiazolinones (especially CMIT ) may in humans by direct contact or through the air cause skin sensitization.