Ethyl cellulose (or ethylcellulose) is a derivative of cellulose in which some of the hydroxyl groups on the repeating glucose units are converted into ethyl ether groups. The number of ethyl groups can vary depending on the manufacturer. Food grade ethyl cellulose is one of few non-toxic films and thickeners which are not water soluble. This property allows it to be used to safeguard ingredients from water. Ethyl cellulose is also used as a food additive as an emulsifier.