Electronic nicotine delivery systems (ENDS), such as vaporizers (vapes) and electronic cigarettes (e-cigarettes), have become increasingly popular in recent years as potentially safer forms of adult tobacco and nicotine use. The popularity of these products has also spread to youth users. In 2020, the Food and Drug Administration (FDA) reported that 3.6 million middle and high school students were current users of e-cigarettes. In 2019, the United States Surgeon General declared e-cigarette use among youth to be an "epidemic." While the FDA finalized a rule in 2016 that included ENDS in the definition of a tobacco product, the majority of regulation of these products is left to the states.