1. White.crystalline powder. 2. very slightly soluble in water 3. freely soluble in acetone Appearance: white or almost white or light yellow crystalline powder,odorless . Use: Mebendazole is used to treat infestations by worms including pinworms, roundworms, tapeworms, hookworms, and whipworms. Mebendazole cas# 31431-39-7