alcohols, and heavy metals, all of which are dangerous to human health. A comparison of 13 common hookah flavors found that melon flavors are the most dangerous, with their smoke containing four classes of hazards in high concentrations. Smokeless tobacco Many types of smokeless tobacco are flavored. Nasal snuff is typically flavored, with common flavors including coffee, chocolate, bordeaux, honey, vanilla, cherry, orange, apricot, plum, camphor, cinnamon, rose, spearmint, Bourbon, Cola, and whisky. Gutka, a chewing tobacco preparation commonly used in parts of India, is commonly flavored, as is naswar, a type of dipping tobacco common in Central and South Asia. Moist snuff (dip), snus, and dissolvables are also often flavored. Accounting for more than half of moist snuff and more than four-fifths of snus sold, flavored smokeless tobacco has been becoming very popular and driving the growth in smokeless tobacco usage in the United States. Use by youth Flavored tobacco products—particularly flavored cigarettes (including menthol), cigarillos, hookah, and electronic cigarettes—are disproportionately preferred by adolescents and young adults. Because of the high availability of these popular flavors, flavored tobacco products are widely used for at least 80% of youth tobacco users. According to the CDC, 67% of high school students and 49% of middle school students who used tobacco products in the past 30 days reported using a flavored tobacco product during that time. Flavored tobacco products promote youth smoking initiation and help young occasional smokers to become daily smokers by reducing or masking the natural harshness and taste of tobacco smoke and increasing the social acceptability of the toxic tobacco product. Menthol appeals to younger or beginning smokers largely because the menthol masks the harshness and discomfort of inhaling smoke, making smoking more palatable. Trying menthols increases smoking initiation among youth and young adults, and menthols users face greater addiction and decreased success in quitting smoking. Young people who use menthol cigarettes are 80% more likely to become life-long smokers than those who use regular cigarettes. Likewise, studies associate youth hookah use with subsequent cigarette use, increased intensity of cigarette use, and decreased success in quitting. A 2016 study found 11- to 16-year-old English children exposed to e-cigarette advertisements highlighting flavored, in contrast to flavor-free e-cigarettes, increased e-cigarette appeal and usage. As such, adolescents were more likely to initiate vaping through flavored e-cigarettes than unflavored ones, and a majority of youth who used an e-cigarette first tried a flavored