The Expert Panel for Cosmetic Ingredient Safety (Panel) reassessed the safety of Methylisothiazolinone, which functions as a preservative in cosmetics. The Panel reviewed relevant animal and human data provided in this safety assessment, and data from the previously published safety assessments of Methylisothiazolinone, and concluded that Methylisothiazolinone is safe for use in rinse-off cosmetic products at concentrations up to 100 ppm (ie, 0.01%) and safe in leave-on cosmetic products when they are formulated to be nonsensitizing, which may be determined based on a quantitative risk assessment or similar methodology.
Keywords: Methylisothiazolinone; cosmetics; safety.