Want a little formaldehyde with that vape pen? E-cigarettes produce high levels of formaldehyde-releasing chemicals at high voltages, according to a letter published in the New England Journal of Medicine today. Given that formaldehyde is well-documented carcinogen, the finding lends support to the idea that e-cigarettes should be subjected to greater regulations — an idea that the FDA plans to rule on soon.

"We simulated vaping by drawing the vapor — the aerosol — into a syringe, sort of simulating the lungs," David Peyton, a chemist at Portland State University who participated in the study, told NPR. "To our surprise, we found masked formaldehyde in the liquid droplet particles in the aerosol."

E-cigarettes don't give off smoke. Users inhale a vapor that's created by heating a nicotine-containing liquid instead. Liquids sometimes taste better at specific temperatures, so users have to adjust the voltage and wattage of the e-cigarette to obtain optimal results. Adjusting these parameters can also affect the amount of vapor produced.

The researchers didn't detect formaldehyde-releasing agents at low voltage levels (3.3V). When vapor was produced at high levels (5.0V), however, they found that the e-cigs actually produce higher levels of formaldehyde-releasing agents than the level of gaseous formaldehyde released by traditional cigarettes. Assuming that these agents carry the same risks as the gaseous formaldehyde produced by regular cigarettes, the lifetime risk of cancer of vaping might be between five and 15 times as high as the risk associated with long-term cigarette use, the researchers conclude.

The vaping industry has dismissed the findings. Gregory Conley, president of the American Vaping Association, told The Verge that the way in which the researchers tested the e-cigarettes was improper. "This machine study used conditions that in no way replicated how actual human beings use vapor products," he says. "Anyone using the vapor product at the high setting would tap out — would stop using the product after two or three puffs — because it is that unpleasant of an experience." Conley also points out that when the e-cigarettes were used properly, "no formaldehyde was detected."