Electronic cigarettes are less harmful than traditional cigarettes, but they aren’t safe. There’s evidence they can damage the lungs, and they’re also a path to nicotine addiction. Last year the percentage of teenagers using nicotine grew at the fastest rate ever recorded for an addictive substance, according to a survey funded by the National Institute on Drug Abuse. The same organization also published a survey that found that children who use e-cigs are more likely to become long-term smokers of regular cigarettes than children who never use them.

Regulators at the Food and Drug Administration have a tough job. How can they preserve e-cigarettes as a tool to help adult smokers while snuffing out the teen smoking epidemic? The answer depends on recognizing the differences between types of e-cigs.

E-cigs are regulated by the FDA under the Tobacco Control Act of 2009. The FDA has a legal obligation to reduce death and disease from tobacco and to assess youth initiation as a key factor in determining the “net public health benefit” of a new tobacco product like e-cigs.

Policies I advanced as FDA commissioner aimed to get smokers off cigarettes and onto less-harmful forms of nicotine delivery. The plans recognized that products for delivering nicotine exist on a continuum of risk, with cigarettes being the deadliest form. Medicinal products such as gum and patches are so safe they can be bought over the counter without a doctor’s prescription. E-cigs are somewhere in the middle.

But the dramatic rise of e-cig use by young people in 2018 demanded that FDA take action. Under policies I implemented, the FDA moved up the deadline for market-approval applications from the e-cig manufacturers to continue selling their products. The FDA will also put new restrictions on the flavored, cartridge-based products favored by kids.