Propylene glycol (PG) is a clear, odorless, and slightly viscous liquid with the chemical formula C₃H₈O₂. It is a clear, odorless, and colorless liquid with a slightly sweet taste. It belongs to the group of organic compounds known as glycols and is derived from propylene oxide, which is produced from propylene, a byproduct of petroleum refining. Propylene glycol is hygroscopic, meaning it...