The secretary of Health and Human Services, Alex Azar and the outgoing commissioner of the Food and Drug Administration, Scott Gottlieb, recently declared the “e-cigarette craze” among teenagers an epidemic. There has been a nearly 80 percent increase in current e-cigarette use among high-school-age teenagers over the previous year, they said, citing the 2018 National Youth Tobacco Survey, and an almost 40 percent increase in teens using e-cigarettes on 20 or more of the past 30 days.