1. “We’re Big Tobacco in disguise.”
When electronic cigarettes first debuted in the U.S. about five years ago, they seemed like a threat to the old-fashioned cigarette industry. The battery-powered devices, which turn nicotine-laced liquid into vapor, promised a less harmful and more socially acceptable alternative to combustible paper-and-tar cigarettes - and they were cheaper, not being subject to hefty tobacco taxes. Already, the underdog industry is on track to hit nearly $2 billion in sales for 2013, tripling its 2012 figures, says Wells Fargo analyst Bonnie Herzog. And although the market for traditional cigarettes is still far bigger - topping $80 billion - Herzog predicts that e-cigarettes could surpass old-fashioned smokes in popularity within a decade. But Big Tobacco brooks no challenge. The Big 3 - Altria Group MO -0.24% , Reynolds American RAI +0.03% , and Lorillard LO +0.03%  - have all begun making their own foray into e-cigarettes in the past two years, a main reason why Herzog says she is “very bullish” on the tobacco stocks.

Not everyone thinks that’s such a good thing. “It’s a new product with the same tobacco industry and the same tobacco-industry tactics to get people to try them,” says Erika Seward, assistant vice president for national advocacy at the American Lung Association. Indeed, e-cigarettes are such a hit, some worry that Americans will get hooked before all the risks are known - much as happened with regular cigarettes. “They’re certainly taking a page out of Big Tobacco’s playbook,” Seward says. Big 3 companies, however, say their only target customers are adults who already smoke, and they support more scientific studies on e-cigarettes. Altria, the manufacturer of Marlboros and the largest of the tobacco companies, for one, says its own research shows that 50% of adult smokers are interested in “innovative types of tobacco products” (such as e-cigarettes, which vaporize tobacco-derived nicotine). The company is exploring how to best meet their needs, says spokesperson Brian May: “Time will tell.”

But even e-cig proponents object to Big Tobacco’s involvement, though from a different perspective: “It’s not helpful to the acceptance of e-cigarettes by the public health community,” says Charles Connor, former president and CEO of the American Lung Association who is consulting with the Electronic Cigarette Industry Group, or ECIG, a trade association representing e-cig makers. “It’s an optics problem for sure, and it will certainly raise a lot of caution flags among those who have to promulgate regulations.” The second largest of the Big 3, Camel cigarette makerReynolds American, however, says it, along with its vapor subsidiary, “are leading the transformation of the tobacco industry,” producing high-quality e-cigarettes “while also meeting societal expectations,” according to spokesperson David Howard, Adds ECIG president Eric Criss, “We don’t want to be anything like the bad old tobacco industry - in our product, or in our sales and marketing. Our goal is complete transparency. We’re not interested in sugar coating things.”

2. “We can’t promise this won’t kill you.”

Anti-smoking advocates and public-health officials at the Centers for Disease Control and Prevention alike concede that e-cigarettes have fewer toxins than regular cigarettes and none of the tar. But that’s no guarantee e-cigs won’t give you cancer or kill you the way tobacco-burning cigarettes are known to do. While traditional smoke carries nearly 5,000 chemicals, more than 50 of which are carcinogens, e-cigarette vapor appears to have far fewer deadly toxins, says Michael Fiore, a physician and director of the University of Wisconsin’s Center for Tobacco Research and Intervention. Still, a relatively small study of two leading brands of e-cigarettes, the Food and Drug Administration found carcinogens in half of the 18 samples it tested, and one sample contained small amounts of a toxic chemical found in antifreeze. Researchers at the University of California–Riverside recently found that “many of the elements” in e-cig vapor “are known to cause respiratory distress and disease,” and in some cases emitted higher concentrations of the elements than cigarette smoke produced.

E-cigarette proponents say the trace levels of toxins are unlikely to be dangerous, but Altria and Reynolds American say they don’t make any health claims about their electronic products, pointing out that the FDA has not ruled any tobacco product less risky than another. Both sides agree that more research is needed on the devices - as well as their secondhand effects. Until then, the industry will only go so far as to say the products are “less harmful” than traditional smokes: “It’s better than a cigarette,” says Criss.

“Are they safer than combustible tobacco? Without a question, yes. Are they 100% safe? I don’t think anyone can say that,” Fiore says. Even the implication that e-cigarettes are a little safer puts some health experts on edge, since companies in the 1970s marketed “lite” and “low-tar” cigarettes as a healthier option, only to learn later that they were equally toxic and deadly. “We don’t need another ‘lite, low-tar’ debacle in the United States,” Seward says.

3. “You didn’t quit smoking.You just think you did.”

Rob Fontano, the owner of an e-cigarette retailer Fort Myers, Fla., says e-cigarettes helped him quit smoking actual cigarettes “cold turkey,” after he’d tried nicotine patches, gum, and prescription Chantix without success. He even says his skin now looks healthier and he can breathe easier at the gym. But his version of “cold turkey” still includes e-cigarettes- which neither anti-smoking advocates nor tobacco companies would call quitting. After all, e-cigarettes contain nicotine, and therefore could keep people hooked on the powerfully addictive drug, Fiore says. Worse, they could increase a smoker’s habit if the person used e-cigarettes in places where they aren’t allowed to smoke - or reactivate the addiction in someone who had successfully quit cigarettes.“Once you provide a means for current smokers to maintain their nicotine addiction when they might otherwise think about quitting, you run the risk of continued and substantial use of deadly combustible tobacco,” Fiore says.

Still, e-cig users and advocates say that smoking cessation is one of the devices’ biggest selling points. A Gallup survey of former smokers in July found that 3% credited electronic cigarettes with helping them quit, compared with 2% who cited prescription drugs and 1% who used nicotine gum. (The rest cited everything from willpower to hypnosis.) Some research has tentatively supported e-cigs for smoking cessation: A recent New Zealand study of smokers attempting to quit found that more than 7% of those aided by e-cigarettes had successfully quit six months later, as had nearly 6% of those using nicotine patches. “The research that exists so far indicates that we might be on to something,” says Connor, the Lung Association president-turned-e-cigarette consultant. “My own personal view is that these will be the game-changers that finally get the smoking rate down below 20%.”

But e-cigarette makers don’t outright advertise that their products help people quit smoking - because they aren’t FDA-approved as a smoking-cessation product.“If a tobacco product consumer is concerned about the health effects from tobacco products, the best thing that they can do is quit,” says May of Altria. People who want to quit smoking can go to smokefree.com to learn about the seven treatments FDA-approved to help, or call 1-800-QUITNOW for counseling.