“Mind if I vape?”

The question may become more common as electronic cigarettes become more popular. The answer, however, remains elusive. Etiquette aside, the health effects of inhaling nicotine vapor (hence the term) are largely unknown. More research is clearly needed, but in the meantime, the U.S. Food and Drug Administration has to start regulating e-cigarettes.

U.S. consumers will spend $1 billion on battery-powered smokes this year, 10 times more than they did four years ago. Are e-cigarettes, which come in such flavors as chocolate and butter rum, a benign device to help people stop smoking? Or are they just a new way to feed an old addiction? How safe, compared with tobacco smoke, is the vapor they create?

No one knows. The small studies that have been done so far hint at both pros and cons; one found that smokers cut back on real cigarettes after trying the electronic kind, while another found particles of metal and silicates in e-cigarette vapor that could cause breathing problems. That there are more than 200 brands containing varying levels of nicotine and other substances only makes it harder to assess their safety.

The FDA has indicated it will begin to regulate e-cigarettes this fall. After a federal judge ruled that it couldn’t classify them as medical devices (because they deliver a drug, nicotine), the FDA will regulate them as tobacco products (because nicotine is derived from tobacco). Unlike regular cigarettes, however, e-cigarettes are not known to be lethal. Wariness is warranted, but it’s safe to assume that their vapors are not nearly as dangerous as tobacco smoke.

The FDA’s approach, therefore -- and that of states and cities that regulate tobacco use -- should be two-pronged: It should find out whether e-cigarettes are indeed safe. And while it does, it should ensure that “vaping” remains restricted to adults who are fully informed of the potential risks.

To begin, e-cigarette makers should be required to report and label all ingredients in the nicotine solutions they use. Even though these deliver fewer poisons than are found in traditional cigarettes, they nevertheless have been found to contain carcinogenic nitrosamines and other harmful impurities derived from the tobacco, as well as the additive diethylene glycol, an ingredient in antifreeze.

Manufacturers should also disclose the amount of nicotine that can be inhaled from their e-cigarettes. Today’s models haven’t been found to give users as large a hit of nicotine as regular cigarettes do, but that may not always be the case. (Some bottles of solution meant to refill e-cigarette cartridges have been found to contain enough nicotine to kill an adult if ingested.) Once more is known about the potential hazards of e-cigarette vapors, the FDA may need to restrict certain substances or place limits on nicotine levels.

Then there is the issue of flavoring -- something the FDA forbids in standard cigarettes. All electronic cigarettes are flavored, so to ban flavoring would be to ban the product entirely. But it’s possible to allow tobacco- or even mint-flavored e-cigarettes and still ban or restrict flavors designed to appeal to children, hard as they may be to define.

While they’re at it, the FDA should also ban sales to those younger than 18 and restrict e-cigarette marketing and advertisements in much the same way it limits them for cigarettes. As for health warnings, the agency will need to wait for more data before deciding what exactly they should say.

States and cities, meanwhile, should include e-cigarettes in their restrictions on smoking in public places and office buildings, and apply the same rules on the retail sale of e-cigarettes as they do to tobacco products. Even in towns where there are few restrictions, bars and restaurants would be wise to prohibit “vaping” until they know whether it pollutes the air.

On the question of taxes, states and cities may want to act gradually. If e-cigarettes are found to be valuable smoking-cessation tools, then they may warrant a tax rate that’s lower than what’s imposed on real cigarettes.

It would be great if e-cigarettes turned out to be the breakthrough that gets people to give up smoking tobacco. In the meantime, we should all be careful that e-cigarettes not perpetuate a habit that society has come a long way toward snuffing out. Sensible regulation can help protect that progress.

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