Electronic cigarettes have grown in popularity as an alternative to traditional cigarette smoking - the idea is that since they are just nicotine vapor, users will not be placed in peril by the 200 toxic chemicals in cigarette smoke.
Still, they are controversial. The government does not allow them to be marketed for smoking cessation because no company is large enough to survive regulatory approval - except tobacco or pharmaceutical companies, which many e-cigarette users regard as the problem.
A new paper in Environmental Science&Technology also contends that potentially toxic compounds in e-cigarette vapor could make them harmful after all. Hugo Destaillats and colleagues analyzed vapor from two different kinds of vaporizers filled with three different refill e-liquids. They identified several vapor components including glycidol -- which hadn't previously been identified in e-cigarette vapor -- formaldehyde and acrolein.
The levels were trace, just like you could detect formaldehyde in a diet soda. You'd have to drink 7,000 such sodas per day to get any effect. The controversial International Agency for Research on Cancer also categorizes glycidol as a probable carcinogen, without ever mentioning the exposure levels need. Acrolein is an irritant. Their testing found that increasing the voltage and heat in a single-coil vaporizer (as opposed to one with a double-coil) triples the aldehyde emissions per puff and bumped up the acrolein levels by a factor of 10.
Additionally, the release of potentially toxic compounds increased with use. These compounds originate from thermal decomposition of propylene glycol and glycerin, two solvents used to formulate most e-liquids.