Electronic cigarettes hit the headlines in July when a concerned member of the public travelling on a coach on the M6 toll motorway in the Midlands called police to say he had seen “smoke” issuing from a bag into which a fellow passenger had been pouring an unknown liquid.

Fearing this was a terror incident, armed police stopped the coach, evacuated the passengers, and closed the motorway before finally declaring the bag and its contents—an e-cigarette and associated paraphernalia—harmless.

It is taking the UK Medicines and Healthcare Products Regulatory Agency rather longer to come to the same conclusion—or, rather, to determine whether the devices should be treated as medicinal products, regulated accordingly, and subject to MHRA medicines marketing authorisation.

The e-cigarette is designed to look and behave like a cigarette but delivers only vaporised nicotine and none of the toxins associated with tobacco to its users, who call themselves vapers rather than smokers. When the user sucks on the device, an atomiser powered by a battery heats and vaporises a mixture of nicotine and propylene glycol, an organic compound with a wide range of commercial uses, including in theatrical “smoke” machines. A written Commons statement by health minister Simon Burns in July suggested they were used by as many as 650 000 in the UK.1