Electronic Cigarette Terminology: Where Does One Generation End and the Next Begin?

IMPLICATIONS: The electronic cigarette (ECIG) research community faces several challenges when it comes to regulatory science; not only is the ECIG market changing at a rapid pace, but the terms used by researchers, health organizations, ECIG users, and ECIG manufacturers/distributors to describe devices are inconsistent. These discrepancies make it difficult to advance science and develop regulations. Although researchers have used "generations" to categorize ECIG device types based on various characteristics, with the constantly evolving ECIG market, it is unclear where one "generation" of devices ends and the next begins.