Public health officials have warned that e-cigarettes, or electric nicotine vaporizers, may undo the work they’ve done to whittle down the number of young people who use tobacco products.

Kids and teens may not understand how addictive nicotine is, they say. And the flavorings, ranging from bubble gum to pineapple, which dress up the liquid nicotine that goes into e-cigarettes, suggest manufacturers may be targeting their products to young people.

We’re just beginning to see concrete data on how teens see e-cigarettes, and the evidence suggests the products may in fact be creating a new generation of nicotine addicts.

e cig parts

“It’s not uncommon for us to go into a classroom, ask students to raise their hand if they have a friend who uses vapes, and see 75 percent of the hands go up,” said Kimberlee Vagadori, MPH, project director for the California Youth Advocacy Network, a statewide youth anti-smoking group.

E-cigarettes hold a small amount of nicotine in liquid form and heat it with a coil as the user inhales.

Kids can use the gadgets right under parents’ and teachers’ noses, literally, because adults don’t recognize the wide range of shapes and sizes they come in, or the odors of all 7,000 available flavors. Users can look like they’re chewing on a pen, and teachers tell Vagadori they mistake the smell of vapes for lotion.

In California, it’s illegal for people younger than 18 to buy electronic cigarettes. But not all states have tweaked their tobacco laws to apply to e-cigarettes. According to the Centers for Disease Control and Prevention (CDC), more than 16 million minors live in states where it’s perfectly legal for them to buy these 21st century cigarettes.

The federal Food and Drug Administration has moved to expand its rights to regulate tobacco products to include the nicotine-based e-cigarettes, but the rule is not yet final. Manufacturers have claimed the devices are not tobacco products, because nicotine can be harvested from nightshade plants other than tobacco.

Read More: American Heart Association Asks FDA to Regulate E-Cigs »

E-Cigarettes Create ‘Pathway’ to Smoking

Many young people who say they would never consider smoking are taking up vaping.

A new study published in the journal Pediatrics is one of the first to address whether teens who use e-cigs would otherwise smoke cigarettes or otherwise not use tobacco products at all.

Read Our Coverage of Youth Who Pick Tobacco »

The answer is that users of e-cigarettes are likely kids who wouldn’t otherwise smoke, the study found. Thomas Wills, Ph.D., interim co-director of the Cancer Prevention and Control Program at the University of Hawaii Cancer Center, compared the risk profiles of e-cigarette users to those of youth who smoke cigarettes.

E-cig smokers’ risk profile placed them at an intermediate point between teens who didn’t use tobacco at all and those who smoked cigarettes. More than two-thirds of all the students surveyed also said they thought the vaporizers were healthier than cigarettes.

“Our interpretation is that e-cigs may be operating to recruit relatively low-risk people to smoking,” said Wills.

Evidence is beginning to suggest that vaping “actually increases interest in smoking, and that’s kind of the smoking gun — no pun intended,” Wills said.

In other words, the vaporizers may give students a more positive view of smoking overall, paving the way for them to smoke cigarettes.

Last month, the CDC issued similar findings. Among teens who had never smoked cigarettes, those who had used e-cigarettes were more than twice as likely to say they intended to try than those who didn’t.

“E-cigs seem to be a stimulus, which is what the prevention community was predicting a year ago, which is that this is just a pathway,” said Barbara Dietsch, senior research associate for WestEd, a nonprofit educational research and development agency that studies learning conditions in California public schools.

Not Your Grandfather’s Cigarette

E-cigarettes, which began appearing in corner stores in 2007, have become a very big business for manufacturers, some of whom are big tobacco companies. U.S. sales totaled roughly $11 billion last year.

But manufacturers are not required to disclose the exact strength of the nicotine cartridges they sell, or include a list of chemical additives and flavors mixed in with nicotine.

There are other lingering questions, too: Because the devices heat the nicotine liquid to different temperatures, do different vapes deliver more or less oomph from the same liquid? Do flavors in vaporizer liquids allow users to take bigger puffs without irritating their throat and lungs, like menthol seems to do in conventional cigarettes?

Young people don’t think of the pocketsize vaporizers, which may be shaped like pens or flash drives, as cigarettes.

“What they’re seeing is that everybody is using them because, for them, it’s not a tobacco product,” Vagadori said.

After decades of public health messaging, teens know that tobacco and cigarettes are bad for them. But they don’t apply these lessons to e-cigarettes.

“They grew up with messages about how smoking tobacco causes lung cancer. They remember the images of the woman Debi Austin who had a hole in her throat, but that doesn’t exist for vaping. There’s no message that these are bad for them, especially long-term,” said Vagadori.

Some teens call e-cigarettes hookah pens and vape pens. They may have read that they are healthier than cigarettes and are sometimes used as a smoking-cessation aid, giving the impression they are medical devices.

E-Cigarette Use ‘Growing Like Wildfire’

Nationally, the rate of teens who have tried e-cigarettes has been doubling each year. The CDC reported that the percentage of U.S. teens who had used e-cigarettes tripled from 2011 to 2013 to roughly 12 percent. Rates of youth who smoke traditional cigarettes have continued to fall.

Wills found that 29 percent of the Hawaiian high schoolers he surveyed had tried e-cigarettes, twice as many as had smoked conventional cigarettes.

Hawaii, unlike California, does not ban sale of the devices to minors, and manufactures have done aggressive advertising, Wills explained. That’s one reason why use there is higher than the national average.

But the Hawaiian numbers may be a sign of what’s to come in the continental United States.

The percentage of California students who said during the 2013-2014 school year that they had tried e-cigarettes was 29 percent — exactly the same percentage Wills found in Hawaii, according to preliminary data WestEd has collected on e-cigarettes and tobacco use. The data have not yet been made public.

The WestEd survey included 1,600 schools in 409 districts in California, but because it didn’t include all school districts, the findings aren’t a full representation of use across the state. Still, with 450,000 students, it is one of the largest surveys to date of e-cigarette use among young people.

The two studies suggest that vaping “is catching on like wildfire, and that California and Hawaii are early adopters, which is what our traditional role has been,” said Tom Hanson, senior research associate at WestEd. Hanson cautioned that California’s numbers may be higher than their national counterparts, partly because surveys word their questions differently.

Young people, in their quest for all things new and exciting, have embraced the devices. Adults, and the bureaucracies they run, have not been able to move as fast. Many schools haven’t even clarified their tobacco policies to explicitly include e-cigarettes, the WestEd researchers said.

“It’s an incredibly fast-moving phenomenon, and I think we as researchers and prevention folks have a lot to learn and to catch up with,” said Hanson. “While there’s so much to learn, there’s no time to learn it because it’s spreading like a wildfire.”