Glycerin (glycerol or propane-1,2,3-triol) is a compound widespread in nature either in free form or, more frequently, as an ester (glycerides). Glycerin can be considered a sugar alcohol formed by hydrogenation from glycerin aldehyde (a C3 monosaccharide). Large quantities of glycerin are synthesized from epichlorhydrin and are generated as a byproduct in soap making and biodiesel production. Glycerin is used as a humectant in the food, beverage, and tobacco industries as well as a solvent, a sweetener, and a thickening agent.
