Angie Monroe was about to yell at her oldest son for leaving another pen in the laundry when she saw a thin, metal cylinder in the bottom of the empty washer.

When she examined it more closely, the Atlanta mother of three teenagers realized it wasn't a pen.

"Honestly, I wasn't sure what it was. But my husband knew right away that it was an e-cigarette," Monroe said. "My heart just sunk, because, although I suspected our son had been smoking, I hadn't had proof until then."

The Monroes researched vaping and ended up with mixed feelings about their son's new habit.

"I don't like the idea of putting anything into your lungs except oxygen," Monroe said. "Some kids use liquids that contain nicotine, and some don't. I never was able to find out what our son was using. I was glad it wasn't a pack of cigarettes, but I worry about the chemicals he's inhaling. Vaping is one of those things we probably won't know the long-term health effects of for many years."

Vaping, designed as a tobacco alternative to help smokers wean off cigarettes, uses vapor to deliver specific amounts of nicotine through an electronic device.

According to the Centers for Disease Control, use among middle and high school students tripled from 2013 to 2014.

The science is less clear when it comes to defining the health effects of inhaling these vapors. Even the U.S. Food and Drug Administration admits it's in the early stages of trying to define public health risks associated with the habit.

Vaping shops are popping up all over metro Atlanta to meet increased demand. Though 18 is the legal age to buy products over the counter in Georgia, it's easy enough for an underage teenager with a debit card to click a box online to have hardware and vaping liquids delivered right to their door.

In flavors banned for cigarettes in the United States because of their appeal to kids, vape liquids — or e-juices — come in many fruity and candy flavors. Their cloying odor was what first clued Conyers parent Lisa Hetzel into her son's vaping activity at home.

"My son had friends sleeping over, and when I woke up in the middle of the night to check on them, I noticed that the room had an overwhelming odor of fruit punch. It was like the strong smell in your face when you mix up a pitcher of Kool-Aid," she said.

There's no way to tell from fragrance alone what might be hidden in the vaping liquid. Many teens inhale the sweet fluids unadulterated.

Common additives include nicotine and caffeine, both substances found in high doses to have negative effects on adolescent brain development. Because buyers choose the amounts of nicotine or caffeine added to their liquid, it's possible for a hit on an e-cigarette to meet or even exceed the levels of nicotine found in a conventional cigarette, or deliver a buzz rivaling an energy drink.

E-cigarettes can also be used to vaporize cannabis oil or melt highly concentrated "dabs," a crystallized form of hashish. These products eliminate the tell-tale odor produced by burning regular marijuana joints, which removes one key clue for parents to detect that their teenagers are getting high.

Unlike tobacco smoke, vaping leaves no trace of odor on the user's breath or clothing. Because of the dangers of exposing young children to secondhand smoke, the lack of it is one reason Marietta parent Haylie Kramer is sold on vaping as a safer, healthier alternative to tobacco. Kramer began vaping in place of smoking cigarettes and would not object if her children try it out when they're older—preferably without nicotine.

"It's a popular habit that may not be as safe or healthy as abstaining, but for now, it is, in my opinion, so much better than the alternative on so many levels, even for teens,:" she said. "If non-nicotine vaping could be embraced instead of the stigma attached to it that just shames it as whole, maybe younger ones would think twice about adding nicotine to their vape juice."

Angela Rodriguez of Covington is ambivalent about her son's decision to vape.

"He had never smoked, so I was confused and worried," she said.

She wondered about illegal substances in the vape, and if vaping would lead to drug use.

"Andrew is a bit of a health nut," Rodriguez said. "He assured me he vapes with no nicotine and that there is nothing illegal going on. He says he just likes the 'feel' of it, that it's relaxing, and also something to do when he is around smokers."

The AJC contacted several Atlanta-area middle and high school administrators and counselors to see if they consider vaping to be a problem at local schools, but none of our emails or voice messages were answered.

Parents and school staff now have more help in the fight against youth access to smoking products.

In early May, the FDA finalized a rule that implemented the Family Smoking Prevention and Tobacco Control Act of 2009. This action creates a federal law prohibiting retailers from selling e-cigarettes, hookah tobacco and cigars to anyone under 18, both in person and online. A photo ID will be required for all purchases beginning Aug. 8.