Isothiazolinones
Isothiazolinones are heterocyclic organic compounds that play an important role within biocides . The basic substance of the group of substances, isothiazolinone , is a compound that contains a sulfur , a nitrogen atom and a carbonyl group in a cyclopentene five-membered ring ( thiaazocyclopentenone ). Five isothiazolinone derivatives are widely used:
| Surname | abbreviation | structure |
|---|---|---|
| Methylisothiazolinone | MIT, MI |
|
| Chloromethylisothiazolinone | CMIT, CMI |
|
| Benzisothiazolinone | BIT |
|
| Octylisothiazolinone | OIT, OI |
|
| Dichloroctylisothiazolinone | DCOIT, DCOI |
|
There is also butylbenzisothiazolinone (BBIT), which is being evaluated in the EU for product types 6, 7, 9, 10 and 13 (as of March 2020).
use
Isothiazolinones are used as preservatives against microorganisms ( bacteria , fungi ) in aqueous dispersions , emulsions and solutions. With their bactericidal and fungicidal effect, they protect cleaning agents, paints , varnishes and adhesives from microbial decomposition, for example . Further areas of application of isothiazolinones are paper production , where they are used to combat slime, cooling and process water and the antimicrobial finishing of textiles; DCOIT and OIT are also used as wood preservatives .
The mixtures CMIT / MIT and MIT / BIT are often used in emulsion paints. For their labeling with the Blue Angel , maximum values for CMIT / MIT of 15 ppm and for MIT / BIT of 200 ppm were not allowed to be exceeded. Since February 2018, emulsion paints with IT mixtures can no longer be awarded the Blue Angel, but the products that were previously awarded the Blue Angel keep the Blue Angel. For labeling with the EU flower, the content is also below 15 ppm CMIT / MIT and max. 500 ppm total isothiazolone content.
In the past, isothiazolinones were also used very often for shower products, shampoos and cosmetics; Because of their effect as contact allergens and a labeling requirement that has now been introduced, use there in Germany is falling sharply.
Biological importance
In addition to the desired effect, ie killing or controlling the growth of microorganisms, isothiazolinones also have undesirable effects. They have a high aquatic toxicity , and some isothiazolinones (especially CMIT) can cause skin sensitization in humans through direct contact or via the air .
Individual evidence
- ↑ Entries for CAS no. 4299-07-4 in the ECHA database on Biocidal Active Substances, accessed on March 3, 2020.
- ↑ Appendix 1 to the award criteria RAL-UZ 102. (PDF) Accessed on February 22, 2017 .
- ^ W. Umbach: Cosmetics and hygiene. Wiley-VCH Verlag, 2004, ISBN 3-527-30996-9 .
- ↑ Roland Irion: Biocides, industrial: Type IV contact allergens. In: Everything about allergology. 2008.