Glycerol

Glycerol, also known as glycerin, is a simple polyol with the chemical formula C3H8O3. It is a colorless, odorless, viscous liquid that is miscible with water. Its three hydroxyl groups classify it as a triol, giving it high polarity and hydration capacity. It is hygroscopic and has a relatively high boiling point for a small alcohol.

Glycerol occurs naturally in fats and oils, where it forms the backbone of triglycerides. It is released during hydrolysis of fats and oils, and is produced industrially by saponification or hydrolysis of triglycerides and as a byproduct of biodiesel production via transesterification.

Used widely in food, cosmetics, and pharmaceuticals, glycerol acts as a humectant, solvent, sweetener, and plasticizer. It helps retain moisture, stabilizes emulsions, and provides smooth texture. In biology and chemistry, glycerol serves as a metabolic intermediate, being converted to glycerol-3-phosphate and feeding into glycolysis.

Glycerol is generally recognized as safe when used in regulated amounts. It has low acute toxicity, though large oral doses can have a laxative effect. It is non-volatile with low inhalation risk, and while not highly flammable at room temperature, it can burn when exposed to sufficient heat.