"It's like the wild, wild West," Hamburg said. "Companies can do whatever they want and they can market however they want."
Use of e-cigarettes, called "vaping", has taken off in a big way, with sales hitting an estimated $2 billion in 2013. An e-cigarette product ranges from $10 to $120, depending on how many charges it provides.
The little metal or plastic tubes that look like cigarettes have been around in some form since 1963, but only became popular within the past decade. Now more than 250 brands have proliferated.
The new regulations would extend limits that are currently on cigarettes to other tobacco products, including e-cigarettes. That means makers will have to register with FDA and disclose what is in them.
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"We expect that the industry won't be delighted," Hamburg said.
E-cigarette enthusiasts say vaping is far safer than smoking cigarettes, and some experts say that may well be the case. Cigarettes and other tobacco products contain hundreds, if not thousand of chemicals, and companies were known to add chemicals to enhance flavor and to make the products more addictive.
Supporters and some researchers say they may be useful in helping people quit smoking what they call combustible cigarettes, but the research is limited. Hamburg says it's important to find out just how people really are using them — whether as an aid to kicking the habit or as a crutch to get them past no-smoking zones.
And most health advocates are suspicious of the motives of e-cigarette makers.
"The tobacco industry are very vigorously looking at alternative products to smoking tobacco and are betting a lot that this will be a product for them that will be viable in the future," said American Heart Association president Dr. Mariell jessup.
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"It's being marketed a lot that the smoke is harmless and we don't know that. We shouldn't be fooled by the promises that these devices, these nicotine delivery systems, are safe."
E-cigarettes contain at the least nicotine and compounds such as propylene glycol, as well as water, to make a flavored mist that looks like smoke and that users can inhale like they would a cigarette.
But Hamburg says no one really knows what else is in them or what the effects are of inhaling the heated-up mixture. "We don't know as much about the safety and risks of e-cigarettes and that is why we want to be able to regulate them," Hamburg told NBC News.