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Mutagenicity of cosmetic products containing Kathon®
Author(s) -
Connor Thomas H.,
Tee Patricia G.,
Afshar Masoud,
Connor Kendall M.
Publication year - 1996
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/(sici)1098-2280(1996)28:2<127::aid-em9>3.0.co;2-c
Subject(s) - chemistry , cosmetics , shampoo , ames test , food science , bacteria , salmonella , organic chemistry , biology , genetics
A variety of shampoos, conditioners, skin‐care lotions, and other cosmetic products contain the biocide 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 TA100 without S‐9. Five of these products and Kathon® 886 were further evaluated in TA100 without and with S‐9. 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 TA100. The remaining two products were considerably more toxic than the other products 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 1,000‐fold lower concentration, and activity was also reduced by the addition of S‐9 mix. S‐9 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 methylchloroisothiazolinone was mutagenic. Additionally, a dichlorinated compound was identified which was also mutagenic. In light of these findings and the reported skin sensitization by Kathon® CG in various cosmetics, we recommend that additional testing be done to assure the safety of products containing Kathon® CG. © 1996 Wiley‐Liss, Inc.