[The e-cigarette: a toxicological box of Pandora].

It is argued by the author that the addition of flavorings to e-cigarette devices presents a major uncertainty in the health risks of these nicotine delivery-systems. These flavorings have usually been tested only for oral uptake situations and not for e-cigarette devices in which unkown and possible hazardous combustion products can be formed. A similar uncertainty exist for the de novo formation of combustion products of humectants....