Analysis Finds Toxic Substances in Electronic Cigarettes

Electronic cigarettes contain traces of toxic substances and carcinogens, according to a preliminary analysis of the products by the Food and Drug Administration.

The findings, which were announced on Wednesday, contradict claims by electronic cigarette manufacturers that their products are safe alternatives to tobacco and contain little more than water vapor, nicotine and propylene glycol, which is used to create artificial smoke in theatrical productions. When heated, the liquid produces a vapor that users inhale through the battery-powered device.

“We’re concerned about them because of what we know is in them and what we don’t know about how they affect the human body,” said Joshua Sharfstein, the F.D.A.’s principal commissioner.

The agency analyzed 19 varieties of cartridges, which hold the liquid, and two cigarettes, one manufactured by NJoy and another by Smoking Everywhere.

The analysis found that several of the cartridges contained detectable levels of nitrosamines, tobacco-specific compounds known to cause cancer. One Smoking Everywhere cartridge was found to contain diethlyene glycol, a common ingredient in antifreeze that counterfeiters have substituted for glycerin in toothpaste, killing hundreds worldwide.

Dr. Sharfstein said the agency was “not sure” what type of effect the diethlyene glycol and other carcinogens have on the human body when inhaled through electronic cigarettes.

The Electronic Cigarette Association, an industry trade group, said in a statement that the F.D.A.’s testing was too “narrow to reach any valid and reliable conclusions” and that its members sell and market their products only to adults.

A statement from the chief executive officer of NJoy, Jack Ledbetter, said a third party had tested its products and found them to be “appropriate alternatives” for cigarettes, but he did not release the findings. The company said its experts would review its tests and the F.D.A.’s.

Electronic cigarettes, which are manufactured in China, are subject to little quality control, Dr. Sharfstein said. The study found the levels of nicotine to vary even in cartridges whose labels claim to have the same amount of nicotine. Some of the cartridges that claimed not to contain nicotine actually did, the analysis found.

The F.D.A. has called electronic cigarettes drug delivery devices and said they should not be allowed in the country. It has turned away about 50 shipments of the devices at the border, but they still continue to be sold in malls nationwide and online. The agency would not comment on whether it planned to ban or seize the devices. In April, Smoking Everywhere sued the F.D.A., claiming that it did not have jurisdiction to bar the electronic devices from entering the United States.

The agency and public health officials are especially worried that electronic cigarettes, which are offered in flavors including cherry and bubblegum, are enticing to children and may be easy for those under 18 to obtain online or in malls.