popsci.com/article/science/e-cigarettes-not-harmless-should-be-regulated-cigs-study-says?dom=PSC&loc=recent&lnk=3&con=ecigarettes-not-harmless-should-be-regulated-like-cigs-study-says
* - pubs.acs.org/doi/full/10.1021/jp300997d
Furthermore, when heated and vaporized, propylene glycol--often used in e-cigarettes to form aerosol particles--can form propylene oxide (*), a recognized carcinogen.
* - pubs.acs.org/doi/full/10.1021/jp300997d
800 K = 980 FPropylene glycol (1) has been found to decompose according to three possible reaction pathways shown in Scheme 1. With a barrier of 91.0 kcal/mol, the first route is a dehydration reaction leading to allyl alcohol (5). The other two possible degradation schemes involve the formation of propylene oxide (2) as an intermediate, which can be formed much more easily than 5 by overcoming a reaction barrier of only 66.5 kcal/mol. Via hydrogen shift, propylene oxide (2) can decompose further, forming acetone (3) or propanal (4) with barriers of 67.0 and 58.6 kcal/mol, respectively. It can be concluded that propanal is the main product of the thermal decomposition of PG. Table 1 summarizes the thermodynamic and kinetic data computed for T = 800 K.