1. TFA provides current MSDS on this page:
http://shop.perfumersapprentice.com/specsheetlist.aspx. (click "SDS U.S." link after any flavor)
2. TFA's current sheet for Hibiscus:
http://shop.perfumersapprentice.com/msds/344638.pdf. It's dated 1/19/2017 - years newer than "shopify" has, though I didn't compare to see what, if anything, has changed.
3. Compare to some other flavorings, perhaps some you feel comfortable vaping. Here are some random excerpts:
Juicy Peach:
http://shop.perfumersapprentice.com/msds/345569.pdf "central nervous system depression. Prolonged or repeated exposure to skin causes defatting & dermatitis"
Passion Fruit:
http://shop.perfumersapprentice.com/msds/344802.pdf "avoid breathing {dust/fume/gas/mist/vapors/spray}" "serious eye damage..."
Vanilla Bean Ice Cream:
http://shop.perfumersapprentice.com/msds/346849.pdf "respiratory sensitization: category 1" "skin corrosion/irritant: category 3"
The MSDS contains all the (standardized, legally-required) warnings for each component *in its pure form*. Sure, it can look horrifying! Remember that none of the flavorings contain 100% of any component that prompted the warnings. This is just how MSDS work. Here's more about MSDS requirements & data provided in general:
http://www.afscme.org/news/publicat...eets/how-to-read-a-material-safety-data-sheet.
In the end, it's always up to us to determine what we're willing to use, of course. TFA provides more ingredient info than most; one can see why others may not provide such detail - but be sure other flavor manufacturers use many of the same molecules.
If you're concerned about the effect of vaporized flavorings on living human tissue, there IS one company that's done such testing. Here's some info about FlavourArt's ClearStream Onward, where you can see test methods & results for that brand:
http://www.clearstreamonward.com/home-en/ .
Outside of TFA and FA, most manufacturers tell us next to nothing. If anyone has more info for other brands, I hope they'll share some links.