Final Report on the Safety Assessment of Cyclomethicone

Abstract

Cyclomethicone is a mixture of cyclic dimethylpolysiloxane compounds used primarily as an emollient and solvent in cosmetic formulations at concentrations from <0.1%to>50%. Cyclomethicone is not significantly absorbed through the skin. Small amounts of Cyclomethicone were absorbed by both humans and monkeys in oral feeding studies. The absorbed Cyclomethicone was detected in both the urine and expired air. Acute oral dose of Cyclomethicone to rats produced no deaths nor any gross lesions. Short-term dermal studies produced no behavioral, local skin, gross, nor histopathological changes. In subchronic inhalation studies in monkeys, no significant differences were found between exposed and unexposed animals. Undiluted Cyclomethicone applied to the intact and abraded skin of rabbits produced little or no irritation in two studies. Ocular studies indicated that Cyclomethicone produced only slight transient conjunctival irritation in washed and unwashed eyes. Cyclomethicone did not produce reproductive effects in rats. Cyclomethicone was not a mutagen when assayed in the Ames test. Cyclomethicone was neither irritating nor sensitizing to human skin in two clinical studies. On the basis of the available data, it is concluded that Cyclomethicone is safe as a cosmetic ingredient in present practices of use.