Electronic cigarettes — billed as a healthier alternative to smoking — may be even more damaging than the habit they replace, experts have warned. The battery-powered devices contain a heating element that turns nicotine-laced liquid in a cartridge into a vapour mist that is inhaled.

 

This produces a sensation similar to smoking the real thing but, manufacturers claim, without the carcinogenic chemicals found in cigarette tar. Experts say in order to vaporise the nicotine solution, the chemical propylene glycol is put into the cartridges, and accounts for up to 90% of their content.

This can cause “acute respiratory system irritation”, claims Dr Elisabeth Pott, director of the Federal Centre of Health Education in Cologne, Germany.

The US FDA, in 2009, analysed e-cigarette cartridges and found traces of the carcinogen nitrosamine and other harmful substances in products from several manufacturers.