Dimethylsiloxanes and silicones (CAS No. 63148-62-9) was evaluated in a mutagenic potential study in albino mice. Groups of 12 Charles River male mice were treated with 5 and 10 g/kg of test fluid, 50 mg/kg methyL methanesulfate, or corn oil by intraperitoneal administration and mated with untreated female mice each week for 6 weeks (18 female mice per each male mouse during the 6 weeks of mating). Females were sacrificed approximately 1 week after mating and pre- implantation losses and early resorptions recorded. The number of pre- implantation losses and early resorptions were similar for the treated and control animals. Therefore, the test fluid was considered not mutagenic.