Dipropylene Glycol Industrial Grade (DPG) is a co product from the manufacture of monopropylene glycol by hydrolysis of Propylene Oxide (PO) with excess water at the high temperature and high pressure. DPG is a distilled product of greater than 99.5% purity and is a mixture of three isomeric chemical compounds.

Propylene Glycol Industrial Grade (PGI) is produced by the high temperature and pressure hydrolysis of Propylene Oxide (PO) with excess water. PGI is a distilled material of greater than 99.50% purity.