(AP) -- Federal health officials said Wednesday they have found cancer-causing ingredients in electronic cigarettes, despite manufacturers' claims the products are safer than tobacco cigarettes.
The Food and Drug Administration said testing of products from two leading electronic cigarette makers turned up several toxic chemicals, including a key ingredient in antifreeze.
"Little is known about these products, including how much nicotine is there and what other chemicals may be there," said FDA's Deputy Commissioner Dr. Joshua Sharfstein.
FDA scientists said they tested 19 varieties of cigarettes, half of which contained forms of nitrosamine, a carcinogen known to cause cancer in humans. Many products which claimed to contain no nicotine actually had low levels of the stimulant.
Agency officials said the "quality control processes used to manufacture these products are inconsistent or nonexistent."
Brands tested by the agency included Smoking Everywhere, marketed by a Florida-based company, and NJoy Cigarettes, based in Scottsdale, Ariz.
The Electronic Cigarette Association said the FDA's testing was too narrow to reach "any valid and reliable conclusions."
NJoy, meanwhile, said it was confident its products were "appropriate alternatives" for smokers.
"NJoy's products have been on the market since at least April 2007 with no reports of adverse health consequences," it said.
Public health advocates have complained the products are aimed at young people and can serve as a "gateway" to tobacco smoking. Many come in flavors, including chocolate, bubblegum and mint.
"Tobacco industry research has demonstrated that fruit and candy flavors increase the social acceptance of cigarettes and curiosity to try the product," said Dr. Jonathan Winickoff, chair of the American Academy of Pediatrics' Tobacco Consortium.
Because electronic cigarettes are not covered by federal tobacco laws, they are also often easier for young people to buy. The Electronic Cigarette Association, however, said its members were only marketing their products to long-time, adult smokers.
Electronic cigarettes produce a nicotine mist absorbed directly into the lungs. Most can easily pass as a tobacco cigarette with slim white bodies and glowing amber tips. They even emit what look like puffs of white smoke.
Manufacturers have touted the products as a healthier alternative to smoking because there is no burning involved, and they don't contain the same hazardous cocktail of cancer-causing chemicals.
Regulators said they have halted 50 shipments of electronic cigarettes at ports and borders since last summer. The FDA said it is authorized to seize the products because - for legal purposes - they are a medical device used to deliver nicotine.
However, the FDA's enforcement attempts have been challenged in federal court by manufacturers. The products are made primarily in China.
FDA officials declined to comment on whether they would take action against the two manufacturers whose products were tested.
The agency did say it's "planning additional activities" to address safety issues with the products, which may include recalls or criminal sanctions.
Sen. Frank Lautenberg, D-N.J., asked the FDA in March to pull electronic cigarettes off the market until they are proven safe. On Wednesday, Lautenberg said the products should be "taken off the market immediately" and consumer safety advocates prodded the agency to do more.
"Any companies selling these products in shopping malls or online should be immediately shut down by the FDA because they are selling an unregulated product," said Dr. Diana Zuckerman of the Research Center for Women and Families.
In an effort to move beyond cigarettes, tobacco companies have introduced a number of smokeless products to keep smokers as buyers of other items. They are trying to convert smokers to products such as moist snuff, chewing tobacco and snus - teabag-like pouches that users stick between their cheek and gum.
R.J. Reynolds spokesman David Howard said the company is focused on being the "total tobacco company," pointing to its products like dissolvable tobacco, rather than technology like e-cigarettes.
Neither Reynolds nor Altria Group Inc.'s Philip Morris USA currently market electronic cigarettes.
Earlier this year, the FDA gained the authority to regulate tobacco products for the first time. However, the agency already could regulate electronic cigarettes because they do not actually contain tobacco.
AP Business Writer Michael Felberbaum in Richmond, Va., contributed to this report.
©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Explore further: Oil-swishing craze: Snake oil or all-purpose remedy?