There are 3 issues here that I can spot.
1. Is it safe to vape for humans.
2. Is it safe enough for the atty.
3. Will it have a good tasting result when
vaping it.
I'll start with item 2, as it is the easiest: Unless you are in a situation similar to the person I saw posting about
vaping mouthwash due to not being able to afford ejuice, even if you kill an atty a week vaping something you like, you are still ahead of the game.
A simple test can be performed by cutting down a soda can, applying heat to the bottom of the can, dripping some of the liquid you are considering onto the bottom of the can and letting it vape, then see what kind of residue it leaves behind.
On to item 1: To my knowedge there is no deffinative scientific testing that has been done on vaping and it's effects on us. There has been much speculation, and deduction and good reaserch of MSDS (material safety data sheets) etc on the most common things we are using, and discussion thereoff.
However none of the information available for any of the ingredients in anything we are vaping have been tested for use in the manner in which we want to use them i.e. vaping. Having said this, the best answer I can give is: Others have done it and are still alive, and apparently healthy, ymmv, use with caution esp. if you have known allergies, a grain of salt etc.
Lastly Item 3: Some posts like one above here report Ok results. I tried a french vanilla from the same company and found it to be much less than Ok for flavor. Further I have noted many more posts of opinions similar to mine of less than good results. The tyical complaint is the grocery store flavorings are too weak for this use, or the high alcohol content results in a similar low flavor result. Finally people do tend to talk about BAD things more than good things so my data may be skewed.
I hope this helps
PS: lorann makes a bananna that is really strong, my wife loves it, and I don't hate it either!