Mutagenicity of cosmetic products containing Kathon®

✍ Scribed by Thomas H. Connor; Patricia G. Tee; Masoud Afshar; Kendall M. Connor

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 541 KB
• Volume: 28
• Category: Article
• ISSN: 0893-6692
• DOI: 10.1002/(sici)1098-2280(1996)28:2<127::aid-em9>3.0.co;2-c

✦ Synopsis

A variety of shampoos, conditioners, skincare Iotions, and other cosmetic products contain the bio cide Kathon@ CG, which is a mixture of two heterocyclic isothiazolinones: methylisothiazolinone and methylchloroisothiazolinone. This mixture and the related biocide, Kathon@ 886, have been shown to be potent sensitizers and bacterial mutagens. Five cosmetic products that list the components of Kathon" on their labels and two that do not were screened for mutagenicity with Salmonella typhimurium TAlOO without S9. Five of these products and Kathon@ 886 were further evaluated in TAl 00 without and with S9. Kathon" 886, a cosmetic product that contained Kathon@, and thin layer chromatography-separated components of Kathon" 886 were identified by GC/MS analysis. Three of the five products that listed Kathon" were direct acting mutagens with TAlOO. The remaining two products were considerably more toxic than the other prod-ucts and could not be evaluated for mutagenicity.

The addition of S-9 reduced toxicity but did not eliminate mutagenicity. The mutagenic evaluation of Kathon@ 886 resulted in a dose response similar to that seen with some cosmetic products but at a 1,OOO-fold lower concentration, and activity was also reduced by the addition of S9 mix. S9 reduced activity both with and without cofactors present. Thin layer chromatography separation of the Components and subsequent identification by GC/MS indicated that methylisothiazolinone was nonmutagenic while mefhylchloroisothiazolinone was mutagenic. Additionally, a dichlorinated compound was identified which was also mutagenic. In light of these findings and the re ported skin sensitization by Kathon" CG in various cosmetics, we recommend that additional testing be done to assure the safaty of products containing Katho@ CG.