E-cigarettes 'expose smokers to more formaldehyde than regular tobacco'
A preliminary study in the raises a new worry about electronic cigarettes - exposure to formaldehyde.
Under certain conditions, taking 10 puffs from an e-cigarette would expose a user to about 2.5 times as much formaldehyde as he or she would get from smoking a single tobacco cigarette, according to the study.
Formaldehyde is the pungent chemical that is used to preserve biological specimens, as well as embalm human bodies. It's used as an industrial disinfectant and as an ingredient in permanent-press fabrics, plywood, glues and other household products, according to the National Cancer Institute.
It is also formed when the propylene glycol and glycerol in e-cigarette liquids and oxygen are heated together.
The World Health Organisation's International Agency for Research on Cancer said formaldehyde can cause leukaemia and nasopharyngeal cancer.
The US Environmental Protection Agency considers the chemical a "probable human carcinogen."