ChEBI: Propane-1,2-diol is the simplest member of the class of propane-1,2-diols, consisting of propane in which a hydrogen at position 1 and a hydrogen at position 2 are substituted by hydroxy groups. A colourless, viscous, hygroscopic, low-melting (-59℃) and high-boiling (188℃) liquid with low toxicity, it is used as a solvent, emulsifying agent, and antifreeze. It has a role as a protic solvent, an allergen, a human xenobiotic metabolite and a mouse metabolite. It is a member of propane-1,2-diols and a glycol.