Boiling point of VG and acrolein question

[Ill_Rev_J]

Ok, I confess to being a noob, and oftentimes a boob, which is maybe why I don't get something that could be plainly obvious. I've read up on numerous threads about the boiling point of glycerin being 290 C, while it can produce acrolein at 280 C. In fact, it's on wikipedia:

https://en.wikipedia.org/wiki/Glycerol

https://en.wikipedia.org/wiki/Acrolein

I've also read about atomizer temperatures being measured as typically being in the 70-80 C range.

So my dumb question is: how is it that the VG is being vaporized at these lower temperatures? And how come we don't taste/smell acrolein, since it would "appear" that in order to go from liquid to gas, acrolein must be produced (280 is less than 290 after all). Is it to do with the pressure being applied in drawing on the PV? The flashpoint of glycerol being around 160 C? Or am I just missing something obvious?

Anyone with a chemistry background who can help me understand what's going on when I 'light up' (the LED activation button that is lol) would help me set my mind at ease. Thanks!

 

[whyanon]

Bump, would like to know as well, as acrolein is a toxic substance.
I know of a chemist/biochemist here on ecf, let me see if i can get him to chime in.

 

[bruiser]

Suggest you look in the media section for the latest study that came out this past Thursday.

 

[Kurt]

First of all, if you add pretty much ANYTHING to pure VG (water, flavorings, etc) the boiling point is decreased dramatically. If I make an unflavored juice with 20% water, it will have a boiling point around 140 C. PG, some actual flavor compounds, water, will all lower the BP a lot.

Second, it is not completely black and white in terms of acrolein production, but not far from it. There have been very trace levels found in vapor, but only when the coil is very hot, much hotter than anything a normal person would vape at, and it has never been found even in extreme cases at a level that would pose harm. A burnt-tasting nasty "dry puff" probably does contain trace acrolein, as well as other pyrolysis products. It burns the nose, and then we add more juice or change coils, we don't continue vaping with it burning the nose. The body will reject it pretty emphatically. You KNOW when something is getting burnt.

Many studies looking at acrolein production from vaping, and results are either there is none or else it is at a harmless trace level, orders of magnitude less than occupational hazard levels. Even if we were vaping pure VG, nothing else in it, there would be virtually no acrolein in the vapor from a wet coil. But a good rule of thumb is if the vape tastes at all burned, it is time to add more juice or use a new coil. Something we have instinctively done for years now.

 

[Ill_Rev_J]

Great, thanks for the bump and thanks especially to you, Kurt for the well-explained reply. (I've seen many of your other posts and know that you are very knowledgable, particularly in the field of chemistry, so I'm privileged to receive your feedback.) I figured something along those lines, but wasn't sure. Probably overdid it on the being worried for my own safety, just better to be educated so that when ANTZ or other fairly ignorant people believe the establishment line, as it were, then I can refute them well. And I guess it reassures me too.

I'm still a bit concerned about vaping with oxidized SS mesh, due to the whole Cr(VI) issue, not to the point that I wouldn't try it, but probably wouldn't stick with it for a long time until further studies can be done. But that's a whole other story...