WCS™ Propylene Glycol

Propylene glycol, also called 1,2-propanediol, resembles ethylene glycol in its physical properties. Unlike ethylene glycol, however, propylene glycol is not toxic and is used extensively in foods, cosmetics, and oral hygiene products as a solvent, preservative, and moisture-retaining agent. Propylene glycol is manufactured in large amounts from propylene oxide, which is obtained from propylene.

Propylene Glycol is a nearly odorless clear liquid with a  mild sweet taste.  Some other names for  it are a-propylene glycol, 1,2-propanediol, 1,2-dihydroxypropane, methyl ethyl glycol  (MEG), methylethylene glycol, PG, Sirlene, Dowfrost.

Web definition for Propylene Glycol according to wikipedia.

Bulk propylene glycol can be converted from glycerol or  glycerin which is a byproduct of biodiesel production. 

As far as uses, it is used in many industries.  Recently it was used in the gulf cleanup as  an oil dispersant.  Propylene glycol is  also used as a moisturizer, emulsifier and carrier for fragrance oils in personal  care and pharmaceutical products.  Furthermore,  propylene glycol is used to create fake smoke for movies. Unlike ethylene glycol, propylene glycol has a low toxicity and is biodegradable making it a great alternative for  antifreezes, deicers and is often used in solar water heating systems and liquid  cooling systems.