Update: Received my order from Essential Wholesale. 16 oz bottles are labled as follows:
PG: Propylene Glycol USP (on the side: natural source)
VG: Glycerine Vegetable, Kosher, FCC, USP. (on the side: natural source)
I'm somewhat befuddled by the FCC thing. I would also like to know what the natural source is for PG. Mark, would you know?
I misspoke previously, FCC is "food chemicals codex" an international compendium that was purchased by the USP in 2006. It is a food quality grading(not a drug/pharmaceutical standard). This seems a very odd VG product, there is no Kosher Vegetable Glycerin listed in the USP, and as I noted before, the website labeling and legal FAQ references the Cosmetic part of the FDC code(not the food or drug part). It's impossible to know exactly what grade of VG this is, but it is not properly labeled to be USP quality.
As for the "natural source" PG, that's certainly a stretch. PG does not occur naturally. It is a synthetically made organic compound. It is usually made, industrially, from propylene oxide(which is made from natural gas) or can be converted from , conveniently, Glycerine(which , of course, is a natural product). So I guess you could say , in a roundabout way, PG is "made" from a natural source ultimately(but then again so is Plastic, and I wouldn't consider that a natural product either).