I forget exactly what he said now, but the guy who runs Decadent Vapors explained to me that flavorings typically need to be 4-8 or up to 20x stronger than in there usages for food. There's actually a bit of a safety concern here because we know that most of these flavorings are GRAS (generally recognized as safe), but that is only for "intended uses", and there isn't many inhalation studies done on 95%+ of flavorings.
I still haven't been able to understand all of the stuff about diacetyl and other possibly dangerous flavorings, but I would look out for volatile ketones, or especially anything shaped like diacetyl with the two Oxygen double bounds right next to each other. For most of these it probably isn't a concern, but some of them really aren't suited for use at amounts appropriate to the 0.1ml syringes. You need to really dilute them. Some flavors we are talking about being used at parts per billion.
Take guaiacol as another example. I'm not worried about the safety from the type of chemical it is, but taste descriptions are given at a concentration of 2ppm or .0002%. Assuming we need 20x because of the small amount of liquid vaporized in each puff on an ecig, you are then at 40ppm or .004%. I want to say that there is another thread here where someone was asking about these chems and scubabatdan said he was using guaiacol at 200ppm or .02%.
Besides the fact that these chems are just hard to work with at these levels without a micropipette, do we really know how much survives being vaporized or how much is absorbed into our lungs? I'm not even going to try to get into that, but the one study I have seen trying to do this (the Leuven one) was terribly flawed. Guaiacol's FEMA PADI (possible average daily intake) is 0.643mg.
How does this relate to the amount you might be getting in a day or month's worth of chronic exposure (vaping)? Which GRAS was Guaiacol published in? What were the health concerns surrounding its use in food? It should be obvious that the point I am trying to make is that you should be careful.
FEMA hasn't investigated this stuff for inhalation at the levels we need to use them. They probably won't because of their attachment to the FDA bureaucracy. If I were to "eyeball it" with regards to guaiacol, we look okay here. It is a savory, smoky type flavor that you probably don't want too much of. But then in other cases, is the chemical you are going to use a prominent part of the mixture and you are using it at 20 or 100x typical levels? Is that then way beyond the levels where chemicals were able to achieve GRAS status for food?
I would try to look into these types of things before using any of these chemicals. Fenaroli's and a lot of other PDF e-books can be found through google pretty easily and I would get a micropipette if you are looking to drop $300 on something. I haven't used any of the "tobacco molecules", just some of the non-tobacco ones tucked away in that section of PA's website. I have the raspberry ketone but haven't used it yet. Koolada (trade name for menthyl
methyl lactate) is a cooling agent.
Note that menthyl lactate is not the same as Koolada. The site listed there does have a lot of good info though IIRC. Koolada can be combined with mint flavors to create menthol alternatives, as well as used with non-mint flavors like vanilla bean ice cream to just give a cooling sensation (think toothpaste).
The only other chem I have and have used extensively is eugenyl acetate. PA's clove flavor is probably mainly eugenol, so EA is an accompaniment to it. I'm also working with some chemicals not listed or available through PA for throat hit with 0-nic and have used those, along with some other flavors, to make a pretty realistic clove-cigarette flavor. Eugenol alone will taste like you are sucking on a clove from your spice rack. You need a lot of other things to even start to get like kretek, and we all know that ecigs will never be exactly like burning plant material.
I might try to do what you are doing some day, but it seems quite difficult relative to other things. There is some Chinese juice manufacturer on here that listed out all of the molecules in its blends, so that might give you some ideas. What I have done is buy every tobacco flavoring I can get from PA/FA/etc. and start to learn about what molecules go into making each of these characteristic tobacco flavors like Burley, Latakia, Perique, etc.
You should be able to get familiar with these first and see what makes them successful. Try to be able to recognize what goes into them and taste them at different concentrations. FA's 7 Leaves has EM and licorice flavor added for instance. I'm sure you can put together some good blends how you are going about it, but I am starting from another angle.
