Electronic cigarettes are to be licensed and regulated as an aid to quit smoking from 2016, and we’ve got the answers to the burning questions you’ve always wanted to ask.

What are e-cigarettes?

(Yui Mok/PA)

An electronic cigarette – also known as a personal vaporiser – is a battery-powered device which simulates smoking, but without tobacco. Most products work by using a coil inside an atomiser to heat liquid nicotine which is then inhaled in an action known as “vaping”.

E-cigarettes are usually either manually switched on or inhalation releases the vapour automatically.

What do they contain?

Smoked cigarettes are shown in an ash tray
(Paul Sancya/AP)

Different brands contain different chemical concentrations, often involving propylene glycol, glycerin, water, nicotine and flavourings

The major difference between them and cigarettes is that they do not contain tobacco – only nicotine, which is highly addictive but much less dangerous.

Are they safe?

(John Stillwell/PA)

Experts generally agree that e-cigarettes must be a safer alternative for people who cannot quit smoking tobacco.

However, there is debate regarding the quality of the evidence put forward to say that e-cigarettes are safe.

What’s the latest row about?

(Rich Pedroncelli/AP)

Public Health England (PHE) published a report in August, described as a “landmark review”, saying best evidence showed e-cigarettes were 95 per cent less harmful than tobacco.

Experts who compiled the study said “vaping” could be a “game changer” for persuading people to quit cigarettes.

They also said there was no evidence that e-cigarettes were a “gateway” into smoking tobacco among children.

Some health charities welcomed the findings but other organisations, including the British Medical Association, expressed caution.

Since then, experts writing in The Lancet and the British Medical Journal (BMJ) have said the main claims in the PHE report were based on “flimsy” evidence, based on one meeting of 12 people.

They said some experts cited by the studies had links to the tobacco industry or e-cigarette firms.

The PHE has rebutted these claims and a statement from 12 organisations said it is clear e-cigarettes are better than tobacco.