The FDA will soon begin regulating e-cigarettes, the agency has announced.

A proposed rule, which the FDA will post online at 9 a.m. Thursday, will seek to place e-cigarettes-along with cigars, pipe tobacco, hookah tobacco, dissolvable tobacco products and nicotine gels-under the FDA's authority to regulate tobacco products.

"Right now it's like the wild, wild west in terms of what people are doing, the products are evolving with no regulatory oversight and being marketed in ways that are very worrisome," FDA Commissioner Dr. Margaret Hamburg told ABC News. "Until we can actually require the companies to give us information about what's in them and how they work, we can't get everything that we need to know, and we certainly, without regulatory authority, can't take some of the actions that might be important to insure the safest use of these products."

E-cigarettes use nicotine liquid, but because the substance is "derived from" tobacco, FDA officials believe they can claim the authority to regulate them, the top FDA official for tobacco products told reporters Wednesday.

Top FDA officials described the proposed rule as a "foundational" move, a "first step" that will allow the possibility of further regulation later, while some basic restrictions would be enacted in the nearer term.

It could take a while before new requirements are put in place. The proposed rule will see a 75-day public comment period, after which the FDA will have to consider those comments-and it won't say how long that could take. If approved, the rule would not go into effect for another 30 days.

WHAT IT MEANS

If the rule is approved…

• Sales of e-cigarettes to minors under 18 years of age will be banned. Through contracts with 46 states to monitor and enforce this existing rule for cigarettes, FDA sends trained adults and minors into retail stores to try to buy them. They'll start covertly trying to buy e-cigarettes and other products 30 days after the rule goes into effect, an FDA official said.

• FDA will ban e-cigarette sales from vending machines, unless the machines are on premises where minors aren't allowed.

• To stay on the market, all e-cigarette manufacturers will have to apply through FDA and get their products approved, and new products in the future will also need approval. Manufacturers will have 24 months (again, after this rule goes into effect, if it does) to submit their applications, and they will be able to continue selling and marketing e-cigarettes in the meantime.

• As part of those applications, e-cigarette manufacturers will have to give FDA information about what's in their products.

• 25 months after the rule goes into effect, e-cigarettes will be required to carry health warnings, but only about the risk of addiction-not cancer, heart disease, or the other risks cigarette packages must mention.

• By bringing e-cigarettes under their regulatory purview, FDA officials said they open the possibility of enacting, and reserve the right to enact, more regulations in the future, such as on flavors and online/TV sales and marketing.

WHAT IT DOESN'T MEAN

• FDA is not seeking to enact bans on TV ads, online sales, online ads, or flavors for e-cigarettes. In taking e-cigarettes under its regulatory scope, FDA says reserves the right to issue new regulations on those down the line. E-cigarettes have existed in a "wild, wild west" of non-regulation, Director of the Center for Tobacco Products Mitch Zeller said, calling the move a "framework" for future regulation.

• FDA is already studying e-cigarettes, and it can test their contents, so the proposed rule (if approved) won't mean the beginning of FDA's examination of e-cigarettes and how they're used. Requiring disclosure of contents will, however, make it easier to assess products, FDA officials said.

REGULATED AS STOP-SMOKING AIDS?

If e-cigarette manufacturers want to claim their products as stop-smoking aids, FDA officials said, they would need to gain a separate type of approval through the FDA Center for Drugs or Center for Devices and Radiological Health.

At present, they would still be required to gain that type of approval if they wanted to claim therapeutic benefits for their products. Currently, their choice is to gain that type of approval or keep selling unregulated.

By imposing regulations on commercial sales of e-cigarettes as non-therapeutic tobacco products, FDA will change the set of choices e-cigarette makers face: claim therapeutic benefits and seek approval as a stop-smoking aid, or don't and seek approval as a tobacco product.

SOME CIGARS REGULATED DIFFERENTLY?

FDA is also seeking to claim authority over cigars and other tobacco products, but it's specifically asking for comments on whether all cigars should be regulated the same.

It's asking the public whether cigars with filters and tips, and cigars that are mechanically assembled or wrapped in something other than whole tobacco leaf, should be regulated differently. In other words, Cohibas and Black & Milds might get treated differently.