Heating flavored e-cigarette liquids produced vapors containing toxic chemicals, a new study found.

Flavors like bubble gum, cotton candy and cupcake have made e-cigarettes attractive to adolescents along with a perception that they are safe. In 2015, 16% of high school students and 5.3% of middle school students used e-cigarettes, according to the National Youth Tobacco Survey.

Researchers studied concentrations of 12 aldehydes like formaldehyde in e-cigarette vapors using three popular brands of e-cigarettes, each of which had a different type of heating mechanism.

Aerosols from the flavored liquids contained large amounts of formaldehyde, acetaldehyde and acrolein, while the liquids themselves did not.

“This clearly demonstrates that these aldehydes are formed not by evaporation but by chemical breakdown of e-liquid components,” authors wrote.

They also determined that the flavored vapors produced significantly more aldehydes than unflavored vapors.

“Production of aldehydes was found to be exponentially dependent on concentration of flavoring compounds,” they wrote.

The amounts of formaldehyde significantly surpassed the exposure limits for workers recommended by the American Conference of Governmental Industrial Hygienists.

“In other words,” authors wrote, “one puff of any of the tested flavored e-cigarette liquids exposes the smoker to unacceptably dangerous levels of these aldehydes, most of which originates from thermal decomposition of flavoring compounds.”

Article Source: (http://www.aappublications.org/news/2016/12/29/ECigaretteVapor122916)