Late Wednesday, the Food and Drug Administration issued a stern warning about those electronic cigarettes so many smokers have been turning to instead of actually lighting up.

Initial test results show dangerous levels of nicotine and a combination of other toxic chemicals.

For years now, Phyllis Brown, like millions of Americans, has been sneaking outside for a smoke.

She's cut back recently, from 2 packs a day to 1 every 3 or 4, switching instead to an electronic or "e-cigarette" that manufacturers have claimed is a healthier alternative.

"My doctor is thrilled, and I'm thrilled," said Brown.

The FDA is not.

Their preliminary tests show e-cigarettes contain several carcinogens and other toxic chemicals, including a key ingredient found in antifreeze.

"We're concerned about how they're being marketed, what's in them, and we certainly don't think people should be using them," said the FDA's Doctor Joshua Sharfstein.

But thousands are.

In just three years, e-cigarettes have become a 100-million dollar business.

Now though several shipments from Chinese manufacturers to distributors like Steve Milin in Chicago have been seized by authorities.

"It's just held. It's in limbo," Milin said.

Along with those who had hoped the battery operated cigarettes were a safer way to smoke.

Another concern for the FDA is that the e-cigarettes have been an alternative to those who are too young to buy tobacco products.

The Electronic Cigarette Association, a group representing manufacturers of e-cigarettes, issued a statement rebuffing the FDA's findings, saying "the FDA's laboratory analysis of electronic cigarettes released is too narrow to reach any valid and reliable conclusions."