Cigarette use remains the leading cause of preventable death in the United States, claiming an estimated 480,000 lives or more each year. Although cigarette use in the United States continues to decline, according to the Centers for Disease Control and Prevention (CDC), 34.2 million American adults smoked cigarettes every day or some days in 2018, and nearly 1.2 million American middle and high school students smoked cigarettes in the past 30 days in 2019. The Food and Drug Administration (FDA), an agency within the Department of Health and Human Services (HHS), is responsible for regulating the manufacture, marketing, distribution, and sale of tobacco products. FDA's Center for Tobacco Products (CTP)-established in 2009 pursuant to the Family Smoking Prevention and Tobacco Control Act of 2009 (TCA; P.L. 111-31)-is primarily responsible for tobacco product regulation. The TCA amended the Federal Food, Drug, and Cosmetic Act (FFDCA) to establish a new chapter IX ("tobacco products"), which, as enacted, applied to cigarettes, cigarette tobacco, roll-your-own tobacco, and smokeless tobacco. However, FDA has the broad authority to regulate any other tobacco products deemed by the agency to meet the definition of a tobacco product and thus to be subject to chapter IX of the FFDCA. In 2016, pursuant to this authority, FDA promulgated regulations (known as "the deeming rule") that extended the agency's authority over all tobacco products that were not already subject to the FFDCA, including ENDS. Because tobacco products have no reported health benefits, FDA's regulation of these products differs in certain respects from FDA's regulation of medical products (e.g., prescription drugs, medical devices). Similar to medical product manufacturers, tobacco product manufacturers are subject to manufacturer requirements, including payment of user fees and premarket review, among other requirements. However, while medical product manufacturers are generally required to meet a standard of safety and effectiveness to receive premarket approval from FDA, tobacco product manufacturers are instead generally required to meet a standard "appropriate for the protection of public health" to receive marketing authorization. Tobacco product manufacturers, importers, distributors, and retailers are also required to comply with tobacco-specific requirements as a result of the harm that tobacco products pose to human health. Examples of such requirements include the development of tobacco product standards, submission of health information to the agency, and distribution and promotion restrictions, among others. In recent years, electronic nicotine delivery systems (ENDS) have become increasingly popular. ENDS is an umbrella term for various types of electronic tobacco products, including electronic cigarettes (e-cigarettes). An e-cigarette is a battery-operated device typically containing nicotine, flavorings, and other chemicals that, when heated, creates inhalable vapor. According to CDC analyses, 8.1 million American adults used e-cigarettes every day or some days in 2018, and about 5.4 million American middle and high school students used an e-cigarette in the past 30 days in 2019. There has been debate in the public health community regarding the impact of ENDS on public health. Some view ENDS as a safer alternative for adult cigarette smokers, while others are alarmed by increased use among youth. Further, the emergence of ecigarette, or vaping, product use-associated lung injury (EVALI) that has resulted in 60 deaths and the hospitalization of 2,711 individuals as of January 21, 2020 has raised further concern among public health stakeholders, Congress, and the general public.