Jonathan E. Fielding, Director of Public Health and Health Officer of the Los Angeles County Department of Public Health, wonders if you know what e-cigarettes, Under Armor, energy drinks, Tesla, and Facebook have in common. Here are some hints: e-cigarettes have become a $2 billion industry and use has doubled among U.S. middle and high school students.

Fielding was referring, of course, to the incredible growth of the listed companies and industries. But unlike clothing, beverages, and cars, e-cigarettes are sold in an industry with almost no regulation. After many delays, the FDA finally released last week its proposed deeming regulations on e-cigarettes. But the long awaited proposed rules fell short of the expectations of many children’s and health advocates by continuing to allow marketing practices such as the sales of liquid nicotine in flavors like bubblegumcaramel apple, and popular cereals. In response, the health agencies of the country’s largest cities urged the FDA at a Capitol Hill briefing to take a stronger stance against the marketing of e-cigarettes to children.

In the absence of any federal oversight of e-cigarettes, health leaders in our big cities stood up to provide leadership to protect our children from nicotine addiction, a role Fielding calls the “engine of innovation.” The four cities represented at the briefing, Boston, Chicago, New York, and Los Angeles, all have taken critical steps against the marketing of e-cigarettes to kids such as banning sales to minors, restricting the placement of e-cigarettes to behind sales counters, requiring retailers to be licensed, and even restricting sales of flavored liquid nicotine within 500 feet of schools. But all say their hands are tied with it comes to marketing restrictions, and call on the FDA to fill that regulation gap.

Marketing to children has long been a Big Tobacco tactic to hook smokers in their youth to become lifelong customers. In fact, nearly nine out of ten smokers began before age 18. But not only do flavors attract young smokers, they also attract young children who mistake liquid nicotine for candy. A recent report from the U.S. Centers for Disease Control found a 200 percent jump in reports of poisonings from liquid nicotine, mostly among children under the age of 5. Just one teaspoon of diluted liquid nicotine can be a deadly dose.

While e-cigarettes do not contain the same level of harmful chemicals as combustible cigarettes, nicotine use alone is a risk factor for heart attack and strokeFive minutes of e-cigarette use can cause lung impairment. And because the vapors in e-cigarettes are currently untested and unknown, Shelley Hearne, Director of the Big Cities Health Coalition warns advocates, “It is not safe to call these products safe.”

Eleven city health departments joined the call to the FDA to address gaps in its proposed rule to protect and promote the public’s health in the marketing, flavoring, and manufacturing of e-cigarettes.