On Thursday, the Food and Drug Administration (FDA) released a proposal to regulate the sale and use of electronic cigarettes, along with other products like cigars, pipe tobacco and hookahs.

The initiative aims to place strict rules on the e-cigarettes industry, which has soared in popularity and is reportedly worth nearly $2 billion, reports the Washington Post. If implemented, the FDA plan would ban the sale of e-cigs to minors, prohibit manufacturers from distributing free samples, require the use of health warning labels on its products and disclose the ingredients. In addition, makers of e-cigarettes would be banned from making health-related claims without scientific evidence. The proposed rules won't, however, prohibit the use of flavors like chocolate or bubble gum, which critics argue might attract children.

"This is an important moment for consumer protection," FDA Commissioner Margaret Hamburg said, adding that tobacco is "the leading cause of death and disease in this country," reported USA Today.

Hamburg said that another reason why regulation is important is because they don't know how many types are on the market.

"It's really the wild, wild west out there," Hamburg said. "Because e-cigarettes are increasingly in the marketplace. They're coming in different sizes, shapes and flavors in terms of the nicotine in them, and there's very worrisome data that show that young people in particular are starting to take up e-cigarettes, especially the flavored ones. And that might be a gateway to other harmful tobacco products."

Advocates say that e-cigarettes help people quit smoking since e-cigs are a battery-operated device that delivers nicotine to users as a vapor. However, because they have not been fully studied, the FDA is unclear about their health risks, how much nicotine users are inhaling and whether they offer any benefits to users.

Some of these regulations will be very restrictive," said Ray Story, the founder of the Tobacco Vapor Electronic Cigarette Association. He added that it could be costly for smaller businesses and slow the growth of a product that advocates say is helpful to smokers who want to quit smoking.

"We're already conducting research and working with partners in the research community to better understand patterns of use of these e-cigarettes and to learn more about the way in which they work and the delivery of the nicotine through e-cigarettes. But until we can really regulate them, we can't have all the information we need, and we can't take all the actions that we might want to be able to best address the public health issues associated with them," Hamburg said, according to CNN.

Because nicotine is a drug, some health experts point out that the concentrated liquid form used in e-cigarettes is highly toxic, even in small doses.