Prevalence and patterns of use Adults An estimated 2.8m adults in Great Britain currently use e-cigarettes.
Of these, 1.4m are smokers and 1.3m have completely stopped smoking. The principal reasons given for e-cigarette use are to support cutting down or quitting tobacco use and to help avoid relapse to smoking. Regular use of e-cigarettes among never smokers is negligible at 0.2%. Early e-cigarettes all looked like cigarettes, however rapid innovation has resulted in a range of product designs. Rechargable devices with a reservoir/tank have increased in popularity, with over two thirds of vapers (71%) using this type of product in 2016. Cigalike or pen-type devices with pre-filled cartridges are used by 23% of vapers and only 3% use disposable products.
Young people Evidence from UK studies indicates that while young people’s awareness of, and experimentation with, e-cigarettes has increased, regular use remains rare and almost entirely confined to those who are current smokers or have smoked in the past. Around 12% of British youth have ever tried e-cigarettes. Around 2% use e-cigarettes at least monthly and 0.5% weekly. Among young people who have never smoked, regular use (at least monthly) is 0.3% or less. Overall, the youth data suggests that e-cigarettes are attracting very few young people who have never smoked into regular use.
E-cigarettes and smoking – renormalising or denormalising?
Concerns have been expressed that the presence of e-cigarettes might act to renormalise smoking, undermining decades of work to tackle the harm from tobacco. So far, there is no evidence that e-cigarettes are acting as a route into smoking for children or non-smokers. The authors of PHE’s independent review of the latest evidence found that: “Since EC [e-cigarettes] were introduced to the market, smoking prevalence among adults and youth has declined. Hence there is no evidence to date Use of e-cigarettes in public places and workplaces 12 that EC are renormalising smoking, instead it’s possible that their presence has contributed to further declines in smoking, or denormalisation of smoking.” The gateway hypothesis – the theory that the use of one drug leads to the use of another drug – features prominently in the academic and public discourse on ecigarettes in relation to young people. In their review, the authors address this, pointing out that “The gateway theory is ill defined and we suggest its use be abandoned until it is clear how it can be tested in this field. Whilst never smokers are experimenting with EC, the vast majority of youth who regularly use EC are smokers. Regular EC use in youth is rare.”
Safety For users E-cigarettes are not risk free, but based on current evidence they carry a fraction of the risk of cigarettes. The authors of PHE’s independent review of the latest evidence concluded that using an e-cigarette (known as ‘vaping’) is around 95% safer than smoking. In an authors’ note published to accompany the report, they explain that this estimate is based on the facts that: the constituents of cigarette smoke that harm health – including carcinogens – are either absent in e-cigarette vapour or, if present, they are mostly at levels much below 5% of smoking doses (mostly below 1% and far below safety limits for occupational exposure). The main chemicals present in e-cigarettes only have not been associated with any serious risk. Their overall assessment is that on current evidence, there is no doubt that smokers who switch to vaping dramatically reduce the risks to their health.
For bystanders There is no published scientific evidence of harm to bystanders from exposure to ecigarette vapour and the available evidence indicates that any risk of harm is extremely low, especially when compared with tobacco smoke. In their independent evidence review conducted for PHE and published in 2014, Professor John Britton and Dr Ilze Bogdanovica concluded that: “Electronic cigarettes do not produce smoke so the well-documented effects of passive exposure of others to cigarette smoke are clearly not relevant…laboratory work suggests that electronic cigarette use in an enclosed space exposes others to nicotine at levels about one tenth Use of e-cigarettes in public places and workplaces 13 generated by a cigarette, but little else. The health risks of passive exposure to electronic cigarette vapour are therefore likely to be extremely low.” Following their assessment of the latest evidence, the authors of PHE’s 2015 evidence review reached a similar conclusion: “EC [e-cigarettes] release negligible levels of nicotine into ambient air with no identified health risks to bystanders.”
Effectiveness for smoking cessation
PHE is clear that the best way for smokers to protect their health and the health of those around them is to stop immediately, completely and permanently. We also recognise that not all smokers are ready or able to stop in one step, and for those people we support the approaches set out in the NICE public health guidance on tobacco harm reduction (PH45). These include: cutting down to quit, reducing the amount smoked and temporary abstinence from smoking, with or without using licensed nicotine-containing products. Our advice is for smokers to switch to e-cigarettes and for e-cigarette users to stop smoking completely. E-cigarettes have rapidly become the most popular stop smoking aid in England.xviii In PHE’s independent review of the latest evidence, the authors conclude that: “Recent studies support the  Cochrane Review findings that EC [e-cigarettes] can help people to quit smoking and reduce their cigarette consumption. There is also evidence that EC can encourage quitting or cigarette consumption reduction even among those not intending to quit or rejecting other support. It is not known whether current EC products are more or less effective than licensed stop-smoking medications, but they are much more popular, thereby providing an opportunity to expand the number of smokers stopping successfully…The evidence on EC used alongside smoking on subsequent quitting of smoking is mixed.” Evidence indicates that e-cigarettes are particularly effective when combined with additional support from local stop smoking services: in 2014-15, smokers in England who combined e-cigarette use with behavioural support had the highest quit rates, with two out of three quitting successfully. A much-cited study by researchers at King’s College London and University College London found that the type of e-cigarette used and the frequency of use had an impact on outcomes. They concluded that daily use of tank models may give smokers a better chance of quitting.
Impact on compliance with smokefree legislation The ASH/CIEH guide
‘Developing an organisational approach to the use of electronic cigarettes on your premises’ advises that: “There are concerns that the appearance and use of electronic cigarettes could undermine our high levels of compliance with smoke- Use of e-cigarettes in public places and workplaces 14 free requirements. However, burning tobacco produces a distinctive and pervasive smell as well as deposits of ash. The Chartered Institute of Environmental Health advises that attempts to pass off smoking as using an electronic cigarette should be able to be detected by a diligent investigator.”
The CIEH policy on use of electronic cigarettes in indoor workplaces and public places acknowledges that the organisation has been made aware of enforcement problems occurring in Wales, including some cases being lost when the enforcement officer’s evidence is insufficient to secure a conviction. Taking this into account, the policy states: “A statutory prohibition on the use of nicotine vapourisers because of a limited number of smokefree legislation enforcement failures cannot be justified. This would be particularly perverse if the evidence is accepted of the effectiveness of nicotine vapourisers in assisting smokers to stop or reduce their smoking and all other risks are considered to be acceptable.”