Analysis of Isothiazolinones and Other Preservatives in Gel-Products Used for Cooling in Japan

Abstract

Recently, two cases of contact dermatitis caused by 2-n-octyl-4-isothiazolin-3-one (OIT) used as a preservative in cooling gel-products has been reported in Japan, and one of the cases was declared a serious product accident based on the “Consumer Safety Product Act.” In this study, the concentrations of three isothiazolinone preservatives (OIT, 2-methyl- 4-isothiazolin-3-one [MIT], and 5-chloro-2-methyl-4-isothiazolin-3-one [Cl-MIT]), seven different parabens, carbendazim (MBC), and tebuconazole (Teb) in 24 cooling gel-products were investigated. OIT was detected in two samples (0.14 μg/g and 2.2 μg/g). MIT was detected in 11 samples at concentrations in the range of 0.12-115 μg/g and Cl-MIT was detected in six samples in concentrations ranging from a trace amount to 16 μg/g. The EU cosmetic limits were used to consider the risk of skin sensitization and the concentrations of MIT and Cl-MIT detected in several samples were over these limit. It is possible for the gel to cause contact dermatitis when the consumer′s weight presses on the gel-product because OIT might penetrate from the gel to the textile surface in the case of a serious product accident. Furthermore, it is possible that using the gel product for the forehead or neck has a similar risk of skin sensitization if the gel-product′s surface tears and the gel containing isothiazolinone preservative leaks out. It is advisable to replace the preservatives in cooling gel-products with non-sensitizing preservatives. All parabens were detected in the gel-products, except benzylparaben, and their concentrations were 12-696 μg/g. MBC and Teb were detected in three samples with concentrations in the ranges of 0.82-54 μg/g and 1.5-25 μg/g, respectively.