E-cigarettes are battery-powered "cigarettes" that turn nicotine-laced liquid into a vapor mist which can be inhaled. Sellers say they are less harmful than cigarettes because they don't have the toxins of burning tobacco. A growing number of people who use them say they are an effective way to quit smoking.

The estimated $100 million in annual sales of e-cigarettes will be threatened when the Food and Drug Administration (FDA) brings their arguments to a federal court next month. The FDA says they want to regulate the products as drug delivery devices, similar to nicotine gum, patches and other nicotine replacement products. If this was to happen, companies would have to provide lengthy and expensive testing in order to prove their product is safe and effective.

Many e-cigarette companies argue that their products are designed to be recreational, and are not quite smoking devices. They say the expensive clinical testing proposed by the FDA would drive many of them out of business or force the industry to go underground.

A number of public health advocates, including the American Association of Public Health Physicians, say that conventional policies for getting people off cigarettes are not working. Smokers should be encouraged to switch to e-cigarettes and other smokeless tobacco products which could reduce tobacco-related disease in the U.S.

In a report released last year, the FDA conducted a preliminary review of a few e-cigarettes and found poor quality control. Some cartridges that claimed not to contain nicotine actually did, and one of the 18 samples had trace amounts of diethylene glycol, a chemical used in antifreeze that is toxic to humans. The FDA says the amount of nicotine delivered varies and isn't standardized, which also raises safety concerns.