This study evaluated the potential 28 day dermal toxicity of methyl disiloxane fluid. The test substance was applied to the skin of Sprague Dawley rats (10 male and 10 female per dose group) at doses of 0, 100, 500 or 1000 mg/kg/day with nonocclusive covering. The material was applied approximately 6 hours per day 5 days per week for 28 days. The animals were observed daily for general appearance, untoward effects, signs of local or systemic toxicity, and death. After 28 days the animals were sacrificed and examined for changes in hematology, clinical chemistry and organ weight. Gross necropsy and histopathological examinations were also conducted. No deaths, signs of toxicity or untoward effects were reported. No treatment related changes were reported in hematological, clinical chemistry or histopathological parameters. Statistically significant decreases in body weight gains were reported in the high dose males in weeks 3 and 4. However, significant decreases in food consumption was also reported at these times. Significant decreases in absolute liver weight were also seen in this group. Histopathology did not demonstrate any cause for these decreases.