May I quote you when I ask? True, they may very well NOT know but they also may very WELL know since due to the two owner's occupations in the medical field... particularly respiration... and their stated goal starting the business. Many SAY their goal is/was to help stop smoking but they DO appear genuine in that to me. Not all vendors are fly-by-night operations to make quick money grabs while it lasts. Anyway, I'll await your answer... if you don't want me quoting, I can paraphrase it as you suggest. I suspect they're on top of things but if not would you please post a link to those "recent studies" so I can forward to them. Thanks.
Sure you can quote me, not that I have any cachet with them
I'm sure not saying any vendor is a fly-by-night operation. I'm saying they may not know what they're selling, because *their* suppliers (flavor manufacturers) don't necessarily release that information. Heck, they don't have to. All this stuff, including diacetyl, is perfectly safe to eat/drink, and these are intended as food flavorings.
Here's a link to the abstract of the most current study I've seen. It's from December:
Evaluation of the hypersensitivity potenti... [Food Chem Toxicol. 2013] - PubMed - NCBI
Here's an excerpt:
Similar to diacetyl (EC3=17.9%), concentration-dependent increases in lymphocyte proliferation were observed following exposure to all four chemicals, with calculated EC3 values of 15.4% (2,3-pentanedione), 18.2% (2,3-hexanedione), 15.5% (3,4-hexanedione) and 14.1% (2,3-heptanedione). .... These results demonstrate the potential for development of hypersensitivity responses to these proposed alternative butter flavorings and raise concern about the use of structurally similar replacement chemicals.
Google the name of the study (Evaluation of the hypersensitivity potential of alternative butter flavorings) to find more discussion and explanation of it.
If your vendor can assure they use flavorings that do not have these chemicals, you'll be able to breathe easy...so to speak