Mono propylene glycol, also referred to as propylene glycol, PG, propan-1, 2-diol, and MPG, is a viscous liquid that is transparent, colorless, and has a distinct odor. It has the chemical formula C3H8O, is water-soluble, and possesses hygroscopic qualities. Due to its low toxicity and low freezing point after mixing with water, MPG is utilized in a variety of industries.