Monopropylene Glycol (MPG) is a derivative of Propylene Oxide (PO) and is produced in a twostep process. The first step is the reaction of PO with water into a mixture of MPG and Dipropylene Glycol (DPG) and the second step is the distillation and purification of the mixture into its two separate components (MPG and DPG) with MPG being the main component.