Bruce, you are clearly very conscientious and I'll certainly be ordering some of your products. The issues i raised are generic, and no way question you motives or integrity. It would be wonderful if your suppliers provided some analytical data, checking their flavorings for acetoin, diacetyl, acetylpropionyl and other diketones, in addition to certifying they blend in no additional diacetyl. I'll be the happiest camper if I can dare to use flavors like waffle, caramel creme, toffee and kona creme again!
OSHA states that "flavorings may be natural or manmade", that diacetyl and related compounds are "natural byproducts of fermentation", and that they contribute to the natural taste of wines, cheese, and fruit, including strawberry and banana.
When I see people vaping brown liquids with 25% flavorings, I wonder why they never stop to wonder if these compounds, about whose inhalation toxicity we know far less than about that of VG, PG and nicotine, are really harmless. Given what we have recently learned about butter flavorings, and how long it took to even start untangling these issues, I would hope people become a little more cautious. It would be tragic if, having escaped tobacco smoke, we got sick from flavorings that seem so innocent.