here), Crown Seven (here), Smoking Everywhere (here), and VapCigs (here).
Tests conducted by Monique Williams and Prue Talbot measured airflow rates required to produce an aerosol, and the number of puffs available per unit, among other things (abstract here).
They reported, “Significant variation was found among e-cigarette brands in the airflow rate required to produce aerosol,…in aerosol density, and in the manner in which e-cigarettes performed over time….Consumers and researchers should be aware that e-cigarettes vary in performance across brands and within models from the same brand, that some brands will require harder inhalation to use than [combustible] cigarettes, and that aerosol density varies between puffs which may affect nicotine delivery.”
This research followed work published last year (abstract here), in which Williams, Talbot and first author Anna Trtchounian used a smoking machine to compare the puffing characteristics and smoke/aerosol densities of Liberty Stix, Smoking Everywhere, Crown Seven and NJOY (here) with those of combustible cigarettes. They found that most e-cigarettes required a much higher vacuum for puffing than commercial cigarettes, and that the vacuum required for Liberty Stix was the lowest of all tested products. In addition, puff strength had to be increased as puff number increased. They also found considerable variation in the maximum number of puffs delivered by the products, which ranged from 177 (Smoking Everywhere) to 313 (NJOY). In the current study, Smoking Everywhere also delivered only 160 puffs, while VapCigs delivered 250 and Crown Seven delivered 400 (no results were presented for Liberty Stix).
There are numerous e-cigarette brands available in retail stores, shopping mall kiosks and online; starter-pack prices range from about $20 to $100. Smokers should be aware of the variability among and within brands, so they won’t reject this cigarette alternative on the basis of one e-cigarette experience. Smokers should talk with consumers who have made the switch; learn about e-cigarette options and observations on the Internet; and try several products, if necessary, to find one that is satisfying.
While e-cigarettes vary widely, they are capable of improving and extending the lives of cigarette smokers.