On May 10, 2016, the Food and Drug Administration (FDA) issued a rule to extend regulatory authority to all tobacco products, including e-cigarettes, that meet the statutory definition of a tobacco product. This so-called “Deeming Regulation” allows FDA to regulate the manufacturing, distribution, and marketing of tobacco products such as e-cigarettes and includes automatic provisions such as youth access restrictions on sales. Although various forms of battery-powered “electronic nicotine delivery systems” (ENDS) devices have existed for more than a decade, their popularity, especially among youth, has increased in the past 5 years, although most recent data show a slight decline. In contrast to combustible tobacco cigarettes, e-cigarettes do not “burn,” and do not contain most of the estimated 7,000 chemical constituents present in tobacco smoke. Thus, it is generally believed that e-cigarettes are “safer” than combustible tobacco cigarettes, yet exposures to nicotine and a variety of other potentially harmful constituents do occur. Harm might also occur if youth who begin their “tobacco” use with e-cigarettes then transition to combustible tobacco cigarettes or if adult cigarette smokers use e-cigarettes to supplement their smoking, rather than quitting combustible tobacco cigarettes completely.

In order to inform the public about the consequences of e-cigarettes and in support of future FDA and congressional action, a thorough and objective analysis of the state of scientific evidence relating to e-cigarettes and public health is needed. To that end, the ENDS Committee was established in December 2016 under the National Academies of Sciences, Engineering, and Medicine, with an ambitious timeline to complete a review of the science that can inform the understanding of public health risks and benefits of e-cigarettes. What are the short- and long-term health risks of regular use of e-cigarettes? What variables of the numerous types of devices and use patterns are important determinants of risk? Are e-cigarettes an effective means to quit smoking combustible tobacco cigarettes? Are e-cigarettes an “initiation pathway” of youth to smoking combustible tobacco cigarettes? These are just some of the important questions addressed by the committee in this report. Where feasible, the committee applied the most important attributes of systematic review methodology to the scientific literature to establish the strength of evidence surrounding the health risks (e.g., direct harmful effects, initiation of smoking) and benefits (e.g., smoking cessation) associated with e-cigarette use. Although the use of these products is relatively new, the committee identified more than 800 peer-reviewed scientific studies in this report. Based on this review, the committee has provided a summary of the current state of knowledge about the health risks and benefits of e-cigarette use, and has provided a series of research recommendations.

I am deeply gratified by the remarkable hard work and insights provided by my fellow committee members and indebted to the tireless and thoughtful work of the National Academies staff that so ably kept us on task throughout the duration of this study.

David L. Eaton, Chair

Committee on the Review of the Health Effects of Electronic Nicotine Delivery Systems