We have no reason to believe they would be a health hazard. Vegetable Glyrecin is approved for food consumption, most flavour concentrates likewise and, nicotin

We have no reason to believe they would be a health hazard. Vegetable Glyrecin is approved for food consumption, most flavour concentrates likewise and, nicotine, well, at worse it could raise someone's blood pressure a bit, but due to the nature of vaping, it has been measured that "the level of cotinine in passive vapers is approximately 1200 times lower than active smokers" [...] "In conclusion, the levels of nicotine absorbed from passive vaping are not only harmless but do not even produce any biological effect (not even heart rate acceleration)" (quoting Dr. Farsalinos). We could, of course, assume that there might be ill effects even thogh we can't even imagine what those would be at this point, however we could do that with practically anything, couldn't we?