James Gennaro is on a mission.

The 56-year-old three-term Democrat from Queens, who lost both his mother and father-in-law to lung cancer, is fresh off a victory in the New York City Council. Earlier this fall the city passed a version of his bill banning the sale of cigarettes to anyone under the age of 21.

For Gennaro, it was a victory born of persistence.

And already, he’s back with a new target: e-cigarettes, which the councilman believes are a way of “re-normalizing smoking.”

While nicotine patches provide a similar jolt to relieve jones-ing smokers, e-cigarettes bring the familiar gestures and rituals of smoking back to bars and even offices.

And so on Thursday, New York City’s City Council will vote on whether to ban electronic cigarettes from offices, restaurants, bars, airports, movie theaters, buses, and virtually every other indoor space where strangers congregate.

E-cigarettes are battery-powered devices that heat nicotine-infused liquid into an inhaleable vapor. The product category includes small disposables that resemble cigarettes and larger, refillable models that look more like hookahs. E-cigarette users, who call themselves “vapers,” see them as a relatively harmless way to get a nicotine fix. Public health advocates, who are celebrating a decades-long decline in smoking, call e-cigarettes Big Tobacco’s latest ploy to keep consumers addicted to a deadly product.

Whatever else they are, one thing is clear: e-cigarettes are big business. First released less than a decade ago in China, they could reach $1 billion in U.S. sales for the first time this year. Many Wall Street analysts are bullish about future growth, especially compared to regular tobacco. If the New York City vote passes, as it is likely to, it will be the highest-profile setback for e-cigarettes in this country. (Earlier this month a similar ban did not pass in Chicago. A spokesperson with the city of Chicago says Mayor Emanuel has indicated that it will be brought up for vote early next year.)

The U.S. Food and Drug Administration does not regulate e-cigarettes, but it is widely expected to expand its tobacco regulation authority to e-cigarettes soon. Nicotine, the addictive element in cigarettes, is a poison. It’s the other elements in cigarettes that cause many of the health problems associated with smoking.

Puff for puff, no one is calling e-cigarettes worse than normal cigarettes. It’s simply that not enough research has been done to determine how dangerous they are. However studies have found dangerous compounds like benzene and formaldehyde in inhaled or secondhand vapor. (It’s not clear that this is true of all brands.) And a study presented this weekend at the American Association for Cell Biology found that prolonged nicotine exposure can lead to a potentially fatal hardening of the arteries, which can cause heart attacks.

Companies are marketing e-cigarettes with the “same tactics that big tobacco has used for generations,” Michael Seilback, of the American Lung Association said. They’re attracting users with sweet flavors, celebrity endorsements, and the soothing invitation to “switch over instead of quit.”

He could, perhaps, have been talking about Blu, a brand purchased last year by Lorillard, the country’s third largest tobacco company. Blu’s products are black tubes distinguished by tips that glow blue when you suck on them. Jenny McCarthy and the actor Stephen Dorff appear in ads hawking the brand as an odorless, stigma-free tobacco alternative they can suck on anywhere. They don’t make any claims about Blu being healthy or helping them quit.

Councilman Gennaro and other e-cigarette foes point to a recent report from the Centers for Disease Control which found that in 2012 about three percent of high schoolers had used e-cigarettes in the last 30 days, about twice as many as in 2011. About three-quarters of those users had also smoked regular cigarettes in the same period.

But E-Cigarettes most devoted backers are convinced of their potential benefits. Talia Eisenberg is a self-described former New York “party girl” who moved to Boulder Colorado to get healthy. There, she said, she couldn’t kick her smoking habit until she turned to vapor. She credits e-cigarettes with her success and, later she co-founded Henley, a company that sells vaporizers and e-cigarette liquid. The name, she says, implies Britishness, like Marlboro or Parliament, but more modern.

Back in October, the company opened Henley’s Vaporium, a trendy e-cigarette shop and café in Manhattan’s SoHo neighborhood. The store sells about 90 flavors of e-cigarette liquid, including vanilla custard and banana nut bread. Oriented to people who want to quit smoking, the liquids are available in five levels of nicotine concentration, as well as some that are nicotine free. Eisenberg denied claims that flavored inhalants were designed to attract kids: “There’s cupcake vodka, but you have to be 21 to get it.”

As an e-cigarette centered business, Henley’s wouldn’t be affected by the New York law and might even see more business from vapers with few other options. Still, Eisenberg opposes the rule. “If they ban [vaping] in public less people will quit and more people will die.”

The evidence doesn’t support her claims. In September The Lancet published a study finding that e-cigarettes were about as effective as nicotine patches in helping smokers to quit. Both showed a success rate below 10 percent.

Eisenberg wasn’t convinced either by the many unanswered questions about e-cigarettes’ health risks. “We don’t have have long term research on cell phones,” she said. “Who knows what they’re doing to our brains?”

Julie Woessner, the unpaid legislative director of a group called The Consumer Advocates for Smoke-free Alternatives (CASAA) wasn’t unimpressed by the Lancet study. Clinical trials didn’t reflect real life situations she said. E-cigarettes, she said, helped her quit smoking after 30 years and her anecdotal evidence suggests that vaping has a “phenomenal success rate in the wild.” (She said CASAA does not accept donations from large tobacco companies.)

Comparing nicotine addiction to caffeine dependency, she said, “People might be dependent on it but it’s not ruining their lives and it’s not ruining their health.”

She added. “I can breathe better. My doctor is thrilled.”

The manufacturers themselves are tight-lipped.

Altria and Reynolds American, the country’s two largest tobacco companies, are both introducing their own e-cigarettes. Neither company claims that the devices help people to quit smoking. “They want to let people come to their own conclusions,” said Tom Mullarkey, an analyst with Morningstar.

David Sylvia, of Altria Client Services, said the company developed an e-cigarette product in response to customer demand for new types of tobacco products. “Our company is not in the business of making products for cessation.”

Councilman Gennaro, who sponsored New York’s proposed ban, agrees. “They’re not in the cessation business,” he says.

“They’re in the addiction business.”