WASHINGTON -- Electronic cigarettes are pitting regulators against some anti- smoking forces over whether to allow sales now and accelerate smoking-cessation efforts or suspend sales until their true safety and effectiveness can be proven. Proponents of the battery-powered devices urge the Food and Drug Administration to consider them a tool for smokers seeking a tobacco-free alternative. The American Lung Association wants them banned unless proven in clinical drug trials. 'The tobacco-control community is kind of split' on e- cigarettes, Kenneth Warner, dean of the University of Michigan School of Public Health, said in an interview. 'Some people are convinced that anything that has any kind of nicotine or tobacco in it must be subject to the FDA's review and approval. Others think it's almost certainly less harmful than cigarettes.' The FDA is appealing a U.S. District Court ruling that the agency lacks authority to regulate the devices as drugs because they are recreational, not therapeutic. Potential users spend $1.2 billion on smoking-cessation products and $80 billion on cigarettes a year, according to the Centers for Disease Control and Prevention. The FDA said e-cigarettes may work with smokers the way methadone clinics wean heroin addicts by giving them a less harmful form of an addictive substance. Most e-cigarettes deliver a flavored, nicotine-filled vapor -- and are sold with starter kits containing atomizers, batteries and cartridges. They are available online starting at about $40. The agency said it has blocked imports of more than 800 e-cigarette shipments since 2008, most from China. 'While nicotine seems to be the primary ingredient in the cartridges, it is simply unknown how many other chemicals are present and in what amounts,' Siobhan DeLancey, an agency spokeswoman, said by e-mail. A 2009 FDA analysis found some nicotine levels exceeded amounts specified in labels, she said. E-cigarette demand is getting a boost from celebrity users like actress Katherine Heigl as well as Internet availability. Heigl puffed on one during an appearance in September on CBS's 'Late Show,' telling host David Letterman the cigarette wasn't harmful. SmokeStik International Inc., the producer of Heigl's e- cigarette, posted a disclaimer on its website after the appearance saying the company doesn't make health or safety claims. The FDA can regulate as drugs cigarette alternatives that carry therapeutic claims, according to the ruling. The U.S. e-cigarette market consists of several dozen closely held companies including Toronto-based SmokeStik, which hasn't received FDA warnings and doesn't market products as smoking-cessation devices. FDA officials warned five companies in September they were making improper health claims. Las Vegas-based E-Cig Technology Inc. violated agency rules by saying on its website that e- cigarettes can 'help you reduce or quit smoking habits,' the agency said in a letter in September. Warning letters were sent to Gamucci America, a unit of Smokey Bayou Inc. in Jacksonville, Fla.; Ruyan America Inc. in Minneapolis; Johnson Creek Enterprises in Johnson Creek, Wis.; and E-CigaretteDirect in Parker, Colo. Ruyan America hasn't sold products containing nicotine in the U.S. since May 2009, the company's president, said Bill Bartkowski. E-Cig Technology, Johnson Creek and E-CigaretteDirect didn't respond to e-mails sent through websites, while Smokey Bayou didn't reply to a voicemail left at a listed phone number. E-cigarettes need the same FDA drug review as nicotine gum, patches and other approved cessation aids, said Howard Marsh, chief medical officer of GlaxoSmithKline's consumer health- care division. Glaxo's Nicorette was the top-selling brand-name drug for nicotine replacement in the year through June, with $144.6 million in sales, or 12 percent of the smoking-cessation market, based on data from IMS Health Inc., a research firm in Norwalk, Conn. 'You've got to be fair to consumers,' Marsh said in an interview. 'They need the reassurance that these products have undergone the same degree of rigor in terms of demonstrating safety and efficacy.' Unless e-cigarette companies can prove the gadgets are safe, 'people should not use them because we don't know what they are,' said Paul Billings, vice president of national policy and advocacy at the American Lung Association in Washington. For Elaine Keller, an e-cigarette user and vice president of the nonprofit Consumer Advocates for Smoke-Free Alternatives Association, the potential for risk is worth the benefit. 'Maybe it's not 100 percent safe, but it certainly is safer,' she said. 