Is the propylene glycol used in juice made from glycerin/glycerol?

[lirruping]

I've been reading a bit on PG and VG and came across some older information about developing a form of PG from the VG, a by-product of biodiesel manufacture. In particular, I found an article from '07 in Biodiesel Magazine which discusses a (then) new technology to do this. The article emphasizes that the new PG that would come from VG as a less toxic, "greener" alternative to the formerly commonly used PG.

So I'm wondering if this process of creating PG from VG has become the industry standard by now, and whether that is the thing we are all vaping when we buy juices made with USP Grade PG.

Thanks for any knowledge or links to further investigate in advance!

 

[Hoosier]

Well PG is PG just like gold is gold. Change anything about the element proportions and it's a different compound. So how non-toxic "old" PG can be any less toxic and still be PG is a complete mystery to me.

I do not know if any facility is starting with VG in PG production. Given the age of the plant here in Indiana that makes PG I seriously doubt they have spent the money to do a complete internal conversion of the processing equipment. A new plant would be the likely candidate for such a thing, but I am not in the industry and have no idea if, or how many, new PG facilities have been built.

Making ethanol through chemical reactions is a well established process in today's world, but you will not find that in the bottles in your local liqueur store. Folks still use yeast for ethanol production. Just because something is possible does not mean it is standard throughout an industry. (And thank goodness it is not, I have enough trouble obtaining supplies to do natural finishes on my wood projects as urethane based finishes have become the "standard" for much of the industry.)

 

[The Ocelot]

I think you need to read your sources a little closer. The names of chemical compounds can be similar, while the products are not the same.

We vape vegetable glycerin/glycerol:

"...a simple polyol (sugar alcohol) compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. The glycerol backbone is central to all lipids known as triglycerides. Glycerol is sweet-tasting and generally considered non-toxic."

There is also Synthetic glycerol which refers to material obtained from non-triglyceride sources. Glycerol may also be produced by various routes from propylene."

But the propylene referred to above, is not propylene glycol.

The above propylene (a.k.a. methylethylene) used to make synthetic glycerol is more properly called Propene (not to be confused with Propane). Propene is an unsaturated organic compound having the chemical formula C₃H₆. Propene is produced from fossil fuels—petroleum, natural gas, and, to a much lesser extent, coal.

On the other hand, we vape Propylene glycol, an organic compound with the chemical formula C₃H₈O₂. Industrially, propylene glycol is produced from propylene oxide CH₃CHCH₂O (for food-grade use).

Going far back to initial production, Propene, Propylene Glycol and Propylene Oxide share a couple of basic properties (Carbon and Hydrogen), but they diverge in more specific components, chemical isolation and preparation for application; like the difference between ethanol (alcohol) (diluted to 3%-40% by volume) in a glass of wine and isopropyl alcohol in rubbing alcohol.

I hope this sets you mind at ease.

I've learned more about chemistry and math from vaping, than I ever learned in school.

Thank you Wikipedia for condensing the information much better than I could.