The Food and Drug Administration on Thursday proposed sweeping new regulations for electronic cigarettes, including a ban on sales to anyone under 18, in the first step toward oversight of a fast-growing industry untouched for years by federal rules.E-cigarette makers would be required to seek FDA approval, list the chemicals in the "e-liquids" that users inhale as vapor, and issue health warnings that the nicotine they contain can be addictive.But unlike the rules for traditional cigarettes, e-cigarette makers would still be free to place TV ads, sell products online, and offer sweetly flavored e-liquids like blueberry and vanilla milkshake.The proposal is the first of a long push toward bringing law to what health groups have called the industry's Wild West, and many expect it could take months or years before the widespread rules take effect.Some of Tampa Bay's e-cigarette makers and retailers voiced relief that the rules governing their young industry, where sales are predicted to hit $2 billion this year, were less daunting than they'd feared."We're more happy than not happy," said Rob Burton, the head of corporate and regulatory affairs for White Cloud Electronic Cigarettes, based in Tarpon Springs. "It could have been a lot worse."E-cigarettes heat a nicotine solution into a wispy cloud of smokeless vapor. Supporters argue they are cleaner, cheaper and safer than the cancer-causing tar and chemicals of tobacco, the country's leading preventable cause of death.The nicotine-misting machines range from cheap "cig-a-likes" with light-up tips to pricier, more complex "mods," which users can upgrade with bigger batteries, refillable e-liquid tanks and electric control displays.Under the proposed FDA rules, e-cig buyers would be required to show photo IDs to prove their age, though public health experts pointed to Internet sales as a potential loophole. Free samples and sales in vending machines accessible by minors would also be banned.The proposed rules come just as Florida lawmakers pass their own bans on e-cig sales to young people, which would take effect July 1. The number of American middle and high school students who tried e-cigarettes doubled from 2011 to 2012, while cigarette smoking among that age range slowed, Centers for Disease Control and Prevention data show.The FDA will take public comment for 75 days before making final changes and could propose further rules as research grows. The rules would also cover cigars, hookahs and pipe tobacco, which like e-cigs have gone for years without regulation.Disclosing the chemicals mixed alongside water and nicotine in e-liquids, manufacturers said, would help set standards for a fledgling industry where some still depend on barrels of chemicals from China and overseas. Fred Jeffery, the owner of Blue Lab Vapors, a Largo e-liquid maker, said, "We have nothing to hide, including our ingredients."Makers will still be allowed to sell existing types of e-cigs while awaiting FDA approval. But some worried the FDA requirements would slow their ability to bring new technology to the market. Dimitris Agrafiotis, a board member of VISTA Truth, a Florida-based e-cig advocacy group, said that would "throw this industry back to the stone age."The change could also squeeze Tampa Bay's smaller e-cig businesses, which have less money to spend on costly data-gathering and regulatory applications. Wells Fargo Securities analyst Bonnie Herzog said the change would benefit "entrenched players," like Big Tobacco giants now piloting their own e-cig lines.Many former smokers credit e-cigs with helping them quit America's $100 billion tobacco industry for good. But public health officials worry e-cigs' explosive growth could addict a new generation to nicotine. Because e-cigs have been popular for less than a decade, research into their health effects has a way to go. Experts say we still don't know the long-term effects of sipping nicotine vapor, whether e-cigs truly help smokers quit, or whether kids who try them are more likely to try cigarettes.University of South Florida marketing department chair Anand Kumar, part of a team researching the branding of e-cigarettes, said that worries of e-cig users moving to real cigarettes have become a key concern as regulation and research continues."There are people out there who fought the tobacco industry for so long," Kumar said, "that the last thing they want is to see new people coming in."Drew Harwell can be reached at [email protected] or (727) 893-8252.