I was reading the study published on 15 May 2014 in The Oxford Journal about carcinogenic particles found in vape. Unsurprisingly higher VG caused lower levels of carcinogens to be present. What I did find surprising is they did a control sample made of Polyethylene Glycol (PEG) and nicotine solution that had no traces of carcinogens found. PEG is what is used in fog machines and has been generally regarded by the vaping community as "not safe to vape", but with new empirical evidence showing it might be "safer to vape" should we start experimenting with PEG?
Looks like PEG was the primary ingredient in Ejuice during the early days, but was removed because anti-Vapers demonized it for being an ingredient in antifreeze. In high doses it can be toxic, but not in the doses you get from vaping. PG was chosen because it is generally regarded as safe by the FDA and EPA. PG vapor has been studied since the 40s and has been found to be beneficial and has anti-viral/bacterial effects when inhaled. The studies on PG vapor were not on vapor produced by heat, which changes the chemical makeup of the molecules; so I've always taken those studies to not really apply to vaping. I guess it comes down to a choice between mildly toxic but not harmful at the levels being used or mildly carcinogenic.
I believe some folks have had success using PEG for THC concentrates. Oils/waxes/ shatters apparently dissolve better in it than PG or VG.
It been a while since l looked into PEG but l believe there is higher chance of diethelyne glycol contamination since both compounds are usually made on the same line.
EDIT: Took some stuff out since I got a little confused lol. Oh and I found the ECF link
http://www.e-cigarette-forum.com/forum/ecf-library/177551-pg-vg-peg.html#post2977320
How is the consistency? Have studies been done (other than the recent one) on its effects for humans at vape temperatures? Does it have a flavor/distinct scent?
It does have a distinct smell. Fog machines are weird.
I'm not sure, I've never vaped it. Looked on Amazon and it seems a little pricy for experimentation. Unless I'm mistaken, PEG was used in early ejuices until it was decided that PG was safer (I don't know what science was behind the change). I have just started doing research myself, so I'm definitely not an expert on the subject.