Justin King enjoys a puff on his lunch break, but he's not smoking regular cigarettes any more. He's using electronic cigarettes, which he says helped kick his 18-year addiction.
"I wasn't feeling good," he said. "I was overweight, I was smoking two packs of cigarettes a day."
E-cigarettes are battery-operated devices, some of which turn nicotine into a vapor that is inhaled instead of smoke. A recent study in Italy found e-cigarettes helped smokers cut the number of cigarettes they smoked in half and many kicked the habit completely.
"I think it could be a revolutionary tool from a public health perspective," said Dr. Riccardo Polosa, a professor of medicine at the University of Catania.
But not everyone is convinced. Some groups say more research is needed on the potential risks of e-cigarettes, concerned they contain chemicals that are toxic and could cause cancer.
"You just should not inhale something into your lungs until it's proven to be safe," said Erika Sward of the American Lung Association.
Hundreds of websites sell e-cigarettes with a variety of flavor cartridges. Groups like the American Lung Association are also worried they could be addictive or serve as a gateway to other tobacco products. They want the Food and Drug Administration to regulate them.
"So that we can first of all understand what consumers are inhaling when they use these products; what the impact on health is," Sward said.
Manufacturers insist e-cigarettes are a healthy alternative to smoking without the health risks.
For King, it was an easy choice. He thinks it saved his life.
"I mean, yeah, I think it did," he said.
This former smoker says e-cigarettes have helped him breathe easier.
The FDA says it intends to propose a regulation so the agency can regulate e-cigarettes the way it does other tobacco products. Several states including Alaska, Idaho, Kansas and Maryland have banned the sale of e-cigarettes to minors.