The federal government should regulate e-cigarettes and states should forbid their sale to minors, but an outright ban would collide with the public health goal of reducing harm where possible, public health experts wrote in the New England Journal of Medicine.

E-cigarettes, battery-operated nicotine delivery devices that look like conventional cigarettes but emit vapor instead of smoke, have become the subject of increasing public health and regulatory debate as their popularity grows. U.S. sales are projected to reach $1.7 billion this year, and studies show their use growing among young people.

Some of the debate relates to whether they are being used to help people quit smoking or whether they are a “dangerous product that could undermine efforts to denormalize smoking,” and a potential “bridge” product to a resurgence in tobacco use, the authors from the Mailman School of Public Health at Columbia University wrote Wednesday in a commentary in the journal.

“Marketing campaigns for e-cigarettes threaten to reverse the successful, decades-long public health campaign to denormalize smoking,” wrote Amy Fairchild, Ronald Bayer and James Colgrove.

Los Angeles has voted to subject e-cigarettes to the same restrictions as other tobacco products, and communities across the country are considering how to respond to their appearance. The U.S. Food and Drug Administration does not regulate e-cigarettes, but a majority of states have asked it to do so.

Using e-cigarettes is known as “vaping,” and liquids used in them come in dozens of fruit and candy flavorings that are added to the nicotine. Their use doubled among young people in 2012 from the year before, according to federal officials.

And marketing has connected with some of the objections to conventional cigarettes. The journal authors note one ad that has talk show host Jenny McCarthy saying, “Smelling like an ashtray is not the ideal aphrodisiac.”

The journal authors note that the discussion of e-cigarettes comes at a time when some advocates are looking to eliminate tobacco use. But they say the devices are supported by “public health professionals who’ve embraced the strategy of harm reduction – an approach to risky behavior that prioritizes minimizing damage rather than eliminating the behavior.”

That strategy underlies such initiatives as providing clean needles to drug users to reduce the diseases from dirty needles.

The authors ask whether victory in the tobacco wars must mean complete abstinence.

Given that 6 million people die each year from tobacco-related causes, and that those are disproportionately among poor people, the authors contend that “an unwillingness to consider e-cigarette use until all risks or uncertainties are eliminated strays dangerously close to dogmatism.”