Vaporshots has the analysis of their VG, PG and nicotine online.
They are all USP grade. Here's for VG:
https://www.vaporshots.com/Articles.asp?ID=255
At the bottom it says:
This product is excipient grade and not intended to be used as an active pharmaceutical
ingredient or for specialist applications, such as parenteral, ocular, inhalation, open wound use, or
applications that require sterile and/or pyrogen-free excipients.
This is inline with that posting in ECF about the only VG suitable for inhalation is the synthetic Glycerin. The product pruity seems to be very good but still not enough to be inhaled. Since vaporshots is posting this report, it's probably one of the better ones out there! Who knows what some vendors are selling....People are talking about getting PG from tractor supply companies!