Propylene Oxide Propylene glycol degrades at sustained temperatures in excess of 500c Whereas e cigarette coils are at worst only about 300c and operate for a brief period Perhaps more pertinently the vapor at approximately 1 mm from the coil of a cartomizer has been measured to be about 56c So the propylene oxide thing is just one of the dozens of highly suspect items in this article And no i am not citing sources you people hash it out yourselves i m just pointing out that your credibility here is nearing the ridiculously low standards of your reputation for credibility This article is an incomprehensible he said she said mess That is all joe