Propylene glycol can be converted from glycerol or  glycerin which is a byproduct of bio-diesel production, early odorless clear liquid with a  mild sweet taste. Propylene glycol is  also used as a moisturizer, emulsifier and carrier for fragrance oils in personal  care and pharmaceutical products.

please note:  The information found here in is for research purposes only and is not meant to be a recommendation for use. If pregnant or suffering from illness consult doctor before using