E-cigarettes have been hailed as a way for smokers to stop using more dangerous tobacco products. For teens, however, they may have the opposite effect.

Attracted by the flavors, the buzz and the opportunity for teenage rebellion that e-cigarettes provide, students are using the devices more and more, and experts worry that e-cigarette use today may make it more likely that the teens will pick up a pack of Marlboros in the future.

And that’s just one of the unknowns surrounding the new phenomenon – one that needs more investigation.

E-cigarettes are used to heat up a flavored, nicotine-infused liquid, producing for the user a vapor that satisfies their cravings but lacks the tar and other carcinogens present in tobacco. That appears to make vaping a healthier alternative for smokers who can’t quit the habit altogether – just like nicotine patches or gum.

But for teens who go straight to vaping, e-cigarettes just create a nicotine addiction, one that can lead later to the use of traditional cigarettes, a growing body of research suggests.

E-cigarettes and the liquid cartridges that feed them are not supposed to be sold to kids under 18, but as with traditional cigarettes, kids find a way to get them. There are even vaping-themed lines of apparel and gear directed primarily at teens.

Schools are struggling with the rising popularity of e-cigarettes as students gravitate toward the small, sleek new devices, which can be used almost anywhere, including school bathrooms, even classrooms, as some officials report.

Talking to The New York Times, administrators at Cape Elizabeth High School say once students pick up the devices, they are having trouble putting them down. When asked why he continued to vape, even after getting in trouble, one student told the vice principal, “I can’t stop.”

Initial research suggests that the student, and others who vape, are more likely to try cigarettes at some point – four times more likely, according to the National Institute of Drug Abuse, though whether it leads more often to habitual smoking is unknown.

But even if the student never moves on to tobacco, he could be in harm’s way.

While vaping is safer than tobacco, the metals in the devices and chemicals in the liquid may be harmful. A study in the journal Pediatrics found increased levels of five carcinogenic compounds in the urine of teenage e-cigarette users.

The fact is, little is known about the long-term effects of vaping, turning today’s teens into what public health experts are calling the “guinea pig generation.”

Turning students into lab rats is unjustifiable, and we should adopt the recommendations of the National Academies of Sciences, Engineering and Medicine, which advocates for further study into e-cigarettes and the various ways they may expose young people to harm.

Otherwise, we are only making students the subjects of an ad hoc study whose results will be known only when it’s too late.