While electronic cigarettes, commonly known as "e-cigs," have a reputation as a tool to help smokers quit, new research suggests they may be just as addictive as traditional cigarettes.
E-cigarettes do not burn tobacco, but they do heat and vaporize liquids that contain nicotine, flavorings and other substances. Previous studies had yet to investigate which of the three types of nicotine - each at various levels of addictiveness - were used in these liquids, and therefore, how likely a user was to get hooked.
Researcher Najat Saliba of the American University of Beirut and his team set out to answer this question by testing commercial samples of the liquids made for e-cigarettes. The results of the study, published in the American Chemical Society's journal Chemical Research in Toxicology, found that "free-base" nicotine - believed to be the only kind that gets absorbed by the body, making it the most addictive - was the most commonly used.
The researchers also found that the concentration of nicotine varied and often didn't match the totals the labels claimed, potentially leading to negative effects among users.
"Products with very low nicotine delivery may not substitute for tobacco cigarettes, so that ECIG use is accompanied by little reduced risk of cigarette-caused disease," Saliba told CBS News in an email. On the other hand, "products with very high nicotine delivery may make quitting ECIGs particularly difficult should users decide to try."
Dr. Daniel Neides, medical director of the Cleveland Clinic Wellness Institute, said that the study provides "critical information."
"It is really quite prudent for the companies to have to label the products so the consumer would know how much nicotine they're actually getting," he told CBS News.
The findings also spell trouble for non-smokers who start using e-cigarettes, as it could lead to nicotine addiction where it was not otherwise present.
"Another major concern is that are the higher concentrations of nicotine going to increase the risk for patients going from the e-cigarettes to regular cigarettes," Neides said.
Scientists have also yet to determine if there are other toxic substances in the vapor of devices, which the FDA does not yet regulate.
Such safety concerns have already moved several states to pass laws banning the sale of e-cigarettes to minors, and several others are considering such legislation.
The most recent numbers from the Centers for Disease Control and Prevention estimate that e-cigarette use among middle and high school students tripled from 2013 to 2014, with 2.5 million students using the devices as of last year. That's prompting experts to warn parents of their potential dangers.
"We want parents to know that nicotine is dangerous for kids at any age, whether it's an e-cigarette, hookah, cigarette or cigar," CDC Director Dr. Tom Frieden said in a statement. "Adolescence is a critical time for brain development. Nicotine exposure at a young age may cause lasting harm to brain development, promote addiction, and lead to sustained tobacco use."
The FDA currently regulates only e-cigarettes marketed for therapeutic use, but it has proposed rules that would extend the agency's authority to cover all of these devices.