Carboxymethyl cellulose (CMC) is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone. It is commonly used as its sodium salt, sodium carboxymethyl cellulose. It is used in food science as a viscosity modifier or thickener and to stabilize emulsions in various products including ice cream.