USP for Rx compounding... it's sold in pharmacy's and It's what I use. Medisca is the brand name.
http://www.health-report.co.uk/ethylene_glycol_propylene_glycol.htmThe Food and Drug Administration (FDA) has classified propylene glycol as “generally recognized as "safe",” which means that it is acceptable for use in flavourings, drugs, and cosmetics, and as a direct food additive.
If you check out that link you'll see a perfect example of how ethylene glycol and propylene glycol are lumped into the same category. Yet there is no direct statement of propylene glycol by itself being anything more than generally safe.
Most of the scare stems from an actual event where a chinese chemicals manufacture passed off industrial grade PG as food grade PG and people either died or got sick, can't remember... because some ethylene glycol was present in the low grade PG.
Currently the FDA claims that trace amounts of ethylene glycol (BAD) were found is some random
ecig carts. Thats why they want to ban them.
I mix my own ingredients from trusted sources and hope for the best. The FDA might be helping to keep the PG pure! So things... could be worse!!!!