Selected Aldehydes Yields in the Aerosol of Commercial Electronic Cigarettes

Over the past few years, electronic cigarettes have rapidly evolved and have been introduced in multiple markets across the world. They are thought to be a potentially less harmful alternative to cigarettes, as they heat a liquid to generate the aerosol instead of combusting tobacco. Electronic cigarettes have different designs, with closed systems (such as cartridges), open systems, and variable power/temperature devices (mods). The aim of this study was to examine the aerosol emissions, with a focus on selected aldehydes of various e-cigarette designs from different markets. We performed the analyses until total liquid depletion to test the products’ consistency. To put the results into perspective, the aerosol constituents of e-cigarettes were compared with smoke from the 3R4F reference cigarette. The selected aldehydes (formaldehyde, acetaldehyde and acrolein) known to result from a temperature dependent oxidation of the aerosol formers, glycerol and propylene glycol, commonly used in e-cigarettes were detectable in most products, with the lowest levels observed in closed systems. Generally higher levels were observed in open systems and especially in mods, operated in different conditions in terms of power output, product orientation on the puffing machine or puffing regimes. The need for standardization work on the assessment of variable power electronic cigarettes is emphasized.