...because I was told that cinnamon flavoring, mainly those containing cinnamaldehyde, were toxic.
I decided to check up on the research, and this is what I found;
>A recent study evaluated in more detail the cytotoxic potential of eight cinnamon-flavored EC liquids in human embryonic stem cells and human pulmonary fibroblasts [Behar et al. 2014]. The authors found that the flavoring substance predominantly present was cinnamaldehyde, which is approved for food use. They observed significant cytotoxic effects, mostly on stem cells but also on fibroblasts, with cytotoxicity associated with the amount of cinnamaldehyde present in the liquid. However, major methodological issues arose from this study. Once again, cytotoxicity was just restricted to EC liquids and not to their vapors. Moreover, the authors mentioned that the amount of cinnamaldehyde differed between liquids by up to 100 times, and this raises the suspicion of testing concentrated flavor rather than refills. By searching the internet and contacting manufacturers, based on the names of samples and suppliers mentioned in the manuscript, it was found that at least four of their samples were not refills but concentrated flavors. Surprisingly, the levels of cinnamaldehyde found to be cytotoxic were about 400 times lower than those currently approved for use [Environmental Protection Agency, 2000].
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4110871/
Just like those studies that examine vapor toxicity by dry-burning the coil, studies on flavor toxicity are not immune from invalid methodologies.
Like Paracelsus said "The dose makes the poison". From Wiki: "Cinnamaldehyde is used in agriculture because of its low toxicity, but it is a skin irritant." Looking at the GHS hazard statements, its pretty benigne, especially considering the concentrations we are at.
YMMV, but when we first started vaping, my wife tried a cinnamon flavor and within 2 days broke out in rashes over about 40% of her body, and had serious throat problems. She quit, I researched and found info on cinnamaldehyde, and slowly convinced her to start again with different flavors. No problems and two years cigarette free. So you may discount the study, but please be careful.
Tasty Vapor Atomic Cinnacide:
https://www.tastyvapor.us/blog/atomic-cinnacide-retirement/
I used to vape a shit ton of that Atomic Cinnacide.
I don't feel like searching but the real story behind them stopping AC was that their supplier LorAnns CHANGED THE RECIPE of their cinnamon baking flavor. The owner of TastyV did a gaschromawhateverograph and found that there were markedly higher concentrations of CLOVE flavor in it. Essentially RUINING it for use in AC. I've been vaping since 2010 and mixing since then too. The recipe for AC was, get this, Loranns cinnamon and PRUNE flavor. YES PRUNE. SOOO DELICIOUS.
But it gave me a WONDERFUL burning sensation in my throat and mouth. and any smoker who tried it REALLY REALLY liked it. But if you got that shit on your hand or skin, it for me at least gave me a red blotch chemical burn. I don't want to know what it did to my fucking lungs. The theory at the time was that lungs being moist and skin being dry, was the difference.
I FIRMLY BELIVE THAT LORANNS CHANGED THE RECIPE TO STOP PEOPLE FROM VAPING IT.
The original Tasty Vapor guy (his name escapes me edit, remembered, GEOFF) was probably buying the original cin flavor by the 50 gallon drum and it only took Loranns a couple years to put a stop to it...Maybe they would be liable in 20 years from supplying it? Or they wanted to open their own line.
IT BURNED SO GOOD THO
This is very interesting. What was the juice?
Cinnamaldehyde is a known respiratory irritant. That said, if you can stand to be near one of those mall candles stores near Halloween, vaping it isn't much different. As others have said, the concentration is what matters, and most ejuice has a very small amount.