Users of cherry-flavoured electronic cigarettes may be exposed to a potentially harmful respiratory chemical, a new study has warned.

Researchers from Roswell Park Cancer Institute (RPCI) in US found that high levels of the respiratory irritant benzaldehyde were detected in the vapour from most of the flavoured nicotine products, with the highest concentrations in vapour from cherry-flavoured products.

Benzaldehyde is a compound used in many foods and cosmetic products. While it appears to be safe when ingested or applied on the skin, it has been shown to cause airway irritation in animals and humans, and may have different effects when heated and inhaled, as when used in vaping.

Researchers measured benzaldehyde levels for 145 different flavoured nicotine products using an automatic smoking simulator and calculated daily exposure to users from 163 e-cigarette puffs.

Their analysis detected benzaldehyde in the vapour from 108 (74 per cent) of the flavoured products studied, and found concentrations of the chemical that were 43 times higher in cherry-flavoured products than in other flavours.

"For e-cigarette users, it is important that they pay attention to how the products are affecting them," said Maciej Goniewicz from RPCI.

"If they notice irritation, maybe a cough or sore throat, when they use e-cigarettes, they might want to consider switching to a different flavouring," Goniewicz said.
The findings were published in the journal Thorax.