Smoking in public places is back - but not as we know it. An estimated 1.3 million people across Britain have now switched to electronic cigarettes, joined by, among others, the supermodel Kate Moss.

The electronic look-alikes, which are shaped and weighted to feel like the real thing, contain a battery and a heating device - this vaporises a nicotine solution contained in a disposable cartridge, giving the ‘smoker’ a nicotine hit without the harmful tar and carbon monoxide produced when tobacco is burned.
Using an e-cigarette is now known as ‘vaping’, referring to the vapour produced.

Because they contain no tobacco, e-cigarettes are not covered by laws banning smoking in a public space, so in theory you can smoke them anywhere - in a car, the pub, and even when you are waiting to pick up your children from the school playground. There is also no age restriction.

Sales of the e-cigarette - invented in 2003 by a Chinese chemist - have rocketed since its introduction to UK shops in 2007. The UK is one of the fast-growing markets for the device - but restaurateurs, train companies and doctors are now calling for their restriction.

Last week, Bruce Poole, the chef-proprietor of Chez Bruce in Wandsworth, South-West London, said he was considering banning them in his Michelin-starred restaurant because of ‘raised eyebrows’.

JD Wetherspoon, the pub chain with over 900 branches throughout the UK, has already banned customers from using e-cigarettes because it’s too difficult to distinguish them from cigarettes.

Some rail companies, including First Capital Connect, have also banned e-cigarettes at their stations and on their trains. And now the British Medical Association has recommended that e-cigarettes should be included in the ban on smoking in public places.

But are they wrong to be so down on e-cigarettes? Many studies have shown they are far less likely to damage health than the traditional version. Professor John Britton, who chairs the Royal College of Physicians Tobacco Advisory Group, says ‘if all smokers in Britain stopped using cigarettes and started on e-cigarettes, we’d save 5 million deaths in people who are alive today’.

But though everyone agrees e-cigarettes are a better alternative, they’re not without side-effects. Users who inhale too deeply, for example, may inhale some of the liquid nicotine instead of the vapour, which could make the dose unsafe.

Although there is no evidence that nicotine causes cancer, it is still a toxin and is extremely addictive. It’s known to have an effect on the cardiovascular system and blood sugar levels. Headache, high blood pressure, even heart arrhythmia are all side-effects of taking too much nicotine into the bloodstream.

E-cigarettes are also not suitable for pregnant women because nicotine passes through the placenta.

Manufacturers can add a range of flavourings such as menthol; most e-cigarettes also contain propylene glycol, which turns to white smoky vapour when heated.

Most studies have found that these additives are not harmful in such small amounts, but there are as yet no long-term studies on the health implications of e-cigarettes.

In Germany, the Federal Institute for Risk Assessment (BfR) says it ‘does recognise that e-cigarettes and their liquids represent a health risk’, and that while potential health risks from inhaling nicotine, propylene glycol, and chemical additives are small, almost any chemical can make its way into a product.

Dr Penny Woods, chief executive of the British Lung Foundation, adds: ‘Concerns have persisted over the range and safety of some of the ingredients found in the vapour that users inhale.’

Another issue is whether e-cigarettes are ‘a legal gateway into cigarette-smoking for people not yet of legally-permitted smoking age’. There is also debate over risks to passive smokers. The BfR has said e-cigarettes shouldn’t be allowed in non-smoking areas because these risks were not known. However, a study published last year in Inhalation Toxicology found the risk was small.

Researchers in New York, reacting to news that indoor e-smoking could be banned, analysed four nicotine solutions and found ‘no significant risk’ of harm to human health for all the vapour samples to children or adults.

The Department of Health currently offers no advice concerning the use of e-cigarettes. They are very lightly regulated - in theory they can be sold to children - though this may change.

The UK body that oversees the regulation of medicines, the Medicines and Healthcare Products Regulatory Agency, says e-cigarettes currently available do not meet appropriate standards of ‘safety, quality and efficacy’ and it plans to regulate them as medicinal products by 2016.

Dermot Ryan, managing director of E-Lites, Britain’s best-selling brand, says the industry already has to comply with strict consumer standards and further regulation would drive up prices and encourage people to go back to tobacco-based cigarettes.

He agrees it is important that people can distinguish e-cigarettes - E-Lites have a green light at the tip, making them easy to identify.

But as research on long-term health effects is under way, another issue is whether e-cigarettes effectively support tobacco smoking - helping smokers maintain their habit in places that ban smoking. ‘Further research is needed to confirm the effectiveness of e-cigarettes for smokers looking to quit,’ says Dr Woods.