Propylene glycol (propane-1,2-diol) is a synthetic, viscous, colorless, nearly odorless diol with a faintly sweet taste. It functions as an effective humectant, solvent, and preservative across food, pharmaceutical, and cosmetic industries. Industrially produced via propylene oxide hydration, it lowers the freezing point of water and serves as a safer alternative to ethylene glycol in antifreeze. In foods, it carries flavors, maintains moisture, and stabilizes emulsions. Its miscibility with water and many organic solvents enables broad formulation use. The compound exhibits low volatility and is recognized for its stability under typical processing conditions.