Intermediate 
We often see our colleagues and friends smoking an e-cigarette. But has vaping started to become less popular? Statistics suggest that vaping among smokers and recent ex-smokers, who are the vast majority of vapers, may already be declining. The  gures will be studied closely by the major e-cigarette companies, which have put millions of pounds into a technology that they thought was growing in popularity.
Figures released in 2014 by the health charity Action on Smoking and Health (ASH) reveal that usage among adults in Britain of electronic cigarettes  which do not contain tobacco and produce vapour, not smoke  has tripled from 700,000 users in 2012 to 2.1 million in 2014.
However,  gures collated by the Smoking Toolkit Study, a research organization that provides quarterly updates on smoking trends, show vapings appeal may be declining. Vaping rates among smokers and ex-smokers rose steadily until the end of 2013, when 22% of smokers and ex-smokers were vaping. But this proportion stopped rising in 2014 before dropping to 19% during the  nal quarter of the year. The drop is described as statistically signi cant by Professor Robert West, who collates the  gures for the Toolkit.
Smokers are the key group for e-cigarette companies because seven out of ten vapers are smokers. Only around 1% of people who have never smoked have tried an electronic cigarette. Numbers who use e-cigarettes while continuing to smoke are going down, West said. Weve only been studying vaping for just over a year, so its a short time period, but we are not seeing growth in the number of long-term ex-smokers or never smokers using e-cigarettes. Vaping rates might change but, at this stage, it looks like theyre staying the same.
The fact that vaping has stopped growing in popularity in the UK seems to be at odds with what is happening in the US, where the technology has been promoted aggressively and where reports suggest it is growing in popularity. However, West questioned the interpretation of US data, which made little distinction between people who had once tried an e-cigarette and those who regularly vaped.
Experts believe it is unlikely that vaping will become fashionable among young non-smokers. Only 1.8% of children are regular users, the ASH study found. Instead, e-cigarettes seem to be most popular among adults who want to quit. While the  gures published this month by Smoking In England show that the use of electronic cigarettes by smokers has stopped rising, their data also shows the huge increase in use since May 2011, said James Dunworth, of ecigarettedirect.co.uk. Our customers are still very happy with the product, and technology and innovation in hardware is improving user experience and helping them to switch from traditional cigarettes.
E-cigarettes behave like a sort of nicotine patch, West agreed. They are more popular than nicotine patches and may or may not be more effective. One-third of quit attempts use e-cigarettes, which makes them by far the most popular method of stopping.
Hazel Cheeseman, director of policy at ASH, said it was too soon to say whether vaping had peaked. Although there are indications that the market hasnt grown in the UK for about a year, there doesnt seem to be a decline in the number of people using electronic cigarettes to help them quit smoking.
The European Commission (EC) is looking at increasing taxes on e-cigarettes, which could have an impact on their popularity. A new EC tobacco directive comes into force in 2016 that will limit the amount of nicotine in e-cigarettes to below their current levels. This may mean vapers will have to increase their usage to get the same effect, again something that may make e-cigarettes more expensive.
West suggested that policymakers should see e-cigarettes as an aid to stopping smoking and not have the same regulations for them as for smoking. There is a tendency among some local authorities and organizations to treat e-cigarettes as cigarettes and ban them in public places and outdoors, he said. It just sounds like youre having a go at vapers and that undermines the public health messages were trying to get out. We have to be careful not to stigmatize e-cigarettes.