(CNN) — Smoke-free devices like e-cigarettes have become a popular way to break the nicotine addiction.

Vapor pens, for example, allow smokers to control the amount of nicotine they receive.

 

But the devices are also being used to smoke synthetic drugs, which can be dangerous, as well as hard for police to detect.

 

“Flakka” is just one of the inexpensive synthetic drugs ravaging South Florida, and there’s a new twist that’s making fighting these drugs even harder.

 

Broward County Deputy Lt. Ozzy Tianga said vaping drugs is so discreet, teens can do it right in school.

“There is no scent,” he said. “They can sit in the back of the room and they think it’s funny. They are vaping and what they are vaping, again I cannot determine.”

And that same secrecy makes it tough for police to know what’s inside any given vape pen — they have to get the contents tested by a lab.

 

A recent study by the Centers for Disease Control found e-cigarette use more than tripled among middle and high schoolers in 2014. It’s not known how much of that is drug-related, but young vape users are posting videos of themselves getting high on YouTube.

The Drug Enforcement Administration is so concerned because synthetics can be so dangerous, no matter how they’re ingested.

 

“We’ve seen time and time again where someone has overdosed and died,” said John Scherbenske, DEA supervisory special agent. There are a significant number of overdoses that are occurring related to these types of drugs.”

All of this is so new, no one’s keeping track, and no one knows just how many people have been injured or have died from vaping synthetic drugs.

 

But emergency rooms are are seeing an increase, and the stories are disturbing. “I have had patients in my practice in the emergency room that I have walked in on that are actually vaping at the bedside,” said Dr. John Cunha of Holy Cross Hospital.

Cunha said a patient was recently discharged after an overdose, went into a restroom on his way out of the hospital, vaped more drugs, and had to be taken back to the ER.

While Cunha said that “I think that these devices do have a role in helping people get off of actual cigarettes, and that they may be proven safer in that case, but in the hands of teenagers and drug abusers, they are definitely very dangerous thing to have.”

 

Vaping devices aren’t classified as drug paraphernalia, so there’s no federal age limit on who can buy them, and shops that sell them are popping up everywhere, on the street and online.