Explained We don't have a description for Butyrolactone. Butyrolactone is a rare cosmetic ingredient, with about 0.0% of the products in our database containing it. What it does: Masking, Solvent CosIng Data CosIng ID: 74772INCI Name: BUTYROLACTONEEC #: Â 202-509-5All Functions: Masking, Solvent