The World Health Organization is recommending restrictions on the new electronic cigarettes, whose manufacturers tout them as a safer alternative to traditional tobacco smokes.
A new WHO report calls the e-cigarettes part of an "evolving frontier filled with promise," but says the new product comes with its own health concerns.
It recommends against promoting them to non-smokers and young people, and banning friut and candy flavors. It would also ban manufacturers from advertising unproven health claims about e-cigarettes.
The WHO says while it is less likely to be as poisonous as real tobacco, the smoke caused by e-cigarettes still poses a threat to non-smokers, children and fetuses.
Its recommendations will be debated at an October conference in Moscow on tobacco control.
Instead of tobacco, e-cigarettes use batteries to heat up nicotine-laced liquid. Smokers exhale a vapor instead of highly toxic second-hand smoke, and still get the nicotine they crave.
Manufacturers say the device can help smokers quit the habit. But scientists say the devices are too new to draw any firm conclusions about the health risks.