Hello everyone I am studying chemistry and have done a lot of research on the PG vs VG debate.
You can read in detail my posts on this subject here:
But to get you interested here are some facts:
Propylene Glycol (PG) has a boiling point of 188 degrees Celcius and there are no breakdown chemical reactions before this temperature. It can't reach a higher temperature in an e cigarette. PG is very safe in the quantities used when e smoking unless one is allergic.
Glycerol (VG) has a boiling point of 290
degrees Celsius which is far higher than PG so obviously it is less efficient at vapourising which makes PG the winner as an e smoking liquid. VG might make visible vapour but it is guarateed
to vapourise less liquid and nicotine in total using the same energy generated from the ecigarette by the laws of physics.
But this is not the real concern, the real concern is that beyond 280 degrees VG starts to break down into HIGHLY TOXIC ACROLEIN this 10 DEGREES LOWER that the biling point for VG!
Now I dont think atomizers get hotter than 280 degrees normally
but what about a malfuntioning one? I am not about to get acrolein poisoning to find out.
Finally, the maximum efficiency of the atomizer is when the liquid reaches its boiling point. I'm sure that it reaches the BP of PG but if it did reach the BP of VG then you have acrolein sythesis. Two reasons not to use VG, but low efficiency aside Acrolein is not something you should risk inhaling.