The “95 per cent less harmful” figure comes from Public Health England’s review “E-cigarettes: an evidence update”, published on 19 August 2015. The review did not measure it. It took the number from a 2014 expert-panel exercise by Nutt and colleagues in European Addiction Research, in which a panel meeting in London in July 2013 rated e-cigarettes at 5 per cent of the harm that cigarettes cause their users. One hundred minus that 5 is where the 95 comes from.
It is therefore an estimate made by a panel of experts, not a measurement of disease in people. The Royal College of Physicians set a similar upper limit in 2016, the figure has been contested since, and the most recent UK reviews, for the Office for Health Improvement and Disparities in 2022 and from the RCP in 2024, describe vaping as a small fraction of the risk of smoking without giving a number. On this website the figure is always attributed and dated, and where we discuss it we show or link the criticism.
The position described here is as at 23 October 2026.
Where the number started
The 2014 paper, “Estimating the Harms of Nicotine-Containing Products Using the MCDA Approach”, was written by Nutt and 11 co-authors and published online on 3 April 2014. MCDA stands for multi-criteria decision analysis. An international expert panel convened by the Independent Scientific Committee on Drugs met for a two-day workshop in London in July 2013 and scored 12 nicotine products against 14 criteria covering harm to users and to others.
Cigarettes scored 100 on the weighted scale. E-cigarettes were rated at about 4 per cent of the maximum harm overall and 5 per cent of the harm to users. These are ratings agreed by the panel, not risks measured in people who vape, and the paper says so: “A limitation of this study is the lack of hard evidence for the harms of most products on most of the criteria.”
The paper also disclosed its funding and one connection. It thanks Euroswiss Health (Switzerland) for funding and the Lega Italiana Anti Fumo for supporting the research, and the editors noted that one panel member had connections with “a company that is associated with one of the largest tobacco industries in the world (BAT: Nicoventures)”. A disclosure of this kind does not show that the ratings were biased. It is information a reader should have when weighing them.
How it became Public Health England’s figure
Public Health England (PHE) commissioned the review from researchers at King’s College London and Queen Mary University of London. Its executive summary was careful: “It has been previously estimated that EC are around 95% safer than smoking. This appears to remain a reasonable estimate.” The review did not produce a new estimate. It judged that the earlier one still held.
The wording grew firmer in PHE’s press release, which was headlined “E-cigarettes around 95% less harmful than tobacco estimates landmark review”, although it also said that “E-cigarettes are not completely risk free”.
Two of the authors, McNeill and Hajek, later published a note that is now attached to the report on GOV.UK. They said the estimate rested on the Nutt panel, endorsed by an expert review (West and colleagues, 2014), together with evidence on toxicant levels, and wrote: “We consider the 5% residual risk to be a cautious estimate allowing for this uncertainty.” They added: “Some flavourings and constituents in e-cigarettes may pose risks over the long term.”
What the Royal College of Physicians said, and when
The Royal College of Physicians (RCP) report “Nicotine without smoke: tobacco harm reduction”, published in April 2016, gave a ceiling rather than a point estimate: “adverse health effects from long-term exposure to constituents of vapour cannot be ruled out. Although unknown, the hazard to health arising from long-term vapour inhalation is unlikely to exceed 5% of the harm from tobacco smoke.”
The RCP’s later review, “E-cigarettes and harm reduction: an evidence review” (18 April 2024), gives no percentage. It says that “vaping, over the short and medium term, poses a small fraction of the risk of smoking”, and that e-cigarettes are “demonstrably less harmful than smoked tobacco to user and bystander alike”. The 5 per cent sentence belongs to the 2016 report, not the 2024 review.
The case against the figure
The Lancet published an editorial, “E-cigarettes: Public Health England’s evidence-based confusion”, in its issue of 29 August 2015. As quoted by Michelle Jongenelis of the University of Melbourne in The Conversation (27 April 2023), the editorial described an “extraordinarily flimsy foundation” and “an almost total absence of evidence”.
The main later critique is an editorial in the American Journal of Public Health in February 2020, “Invalidity of an Oft-Cited Estimate of the Relative Harms of Electronic Cigarettes”, by Thomas Eissenberg, Aruni Bhatnagar, Simon Chapman, Sven-Eric Jordt, Alan Shihadeh and Eric K. Soule. As reported by VCU News (8 January 2020), the authors called the claim “outdated, misleading and invalid”. They argued that the panel lacked hard evidence, and that devices have changed so much since the original study that “even if the original estimate was valid in 2013, it can no longer apply.” They called the figure a “factoid”: “unreliable information repeated so often that it becomes accepted as fact”.
Eissenberg, of Virginia Commonwealth University, put his own position this way: “We don’t know whether e-cigarette use is as lethal as combustible cigarette use, less lethal than combustible cigarette use, or more lethal.” The Conversation (27 April 2023) also reported that some of the researchers behind the estimate had links to the tobacco industry.
These criticisms go to the precision and the origin of one number. They do not show that vaping is as harmful as smoking. Questioning the precision of the 95 per cent figure is not the same as disproving the conclusion that vaping is substantially less harmful than smoking. Eissenberg himself says the answer is unknown, not that the two are equal.
Dropped, not withdrawn
The figure outlived the 2015 criticism. In February 2018, announcing its next evidence review, PHE quoted its Director for Health Improvement, Professor John Newton: “vaping is a fraction of the risk of smoking, at least 95% less harmful”.
By 2022 the number had gone from the official language. “Nicotine vaping in England: 2022 evidence update”, published for the Office for Health Improvement and Disparities on 29 September 2022, says that “in the short and medium term, vaping poses a small fraction of the risks of smoking”, and that “vaping is not risk-free, particularly for people who have never smoked”. Its main findings give no percentage.
Stopping using a number is not the same as withdrawing it. When we last searched, on 3 October 2026, we found no statement from the Office for Health Improvement and Disparities, the UK Health Security Agency or the RCP withdrawing the figure. The 2015 report is still on GOV.UK, and we still see the figure quoted as if it were the current UK position.
What the figure does not establish
- It is relative, not absolute. Every UK body cited here says vaping is not risk free.
- It is a panel’s rating, made in July 2013, of the products available then. It is not a measured health outcome.
- It says nothing about people who have never smoked.
- It says nothing about young people. The RCP in 2024 said more should be done to reduce the appeal of e-cigarettes to “people who do not smoke, including children and young people”.
- It cannot speak to unregistered or drug-laced liquids in Malaysia today. Our guide to vaping and quitting smoking covers that separately.
How MOVE uses it
Wherever the 95 per cent figure appears on this website, it is attributed to Public Health England and dated 2015. Where we discuss it, we say that it is contested and we show or link the criticism. We do not state it as a fact about vaping. We state it as an estimate somebody made, at a time.
The critique of the figure is one of the eight criticisms answered on The case against us, which also says where MOVE agrees with its critics. Why we publish the case against us explains that page.
The debate over the 95 per cent figure should not distract from the wider body of evidence on the relative risks of vaping and smoking. The most recent UK reviews, for the Office for Health Improvement and Disparities in 2022 and from the RCP in 2024, both conclude that in the short and medium term vaping poses a small fraction of the risk of smoking. The evidence supports the conclusion that vaping is less harmful than smoking cigarettes. The Cochrane living review, in its version published on 26 August 2026, reports high-certainty evidence that nicotine e-cigarettes help more people who smoke to stop than nicotine replacement therapy does. It is a review of quitting among adults who smoke, not a safety review. At the same time, MOVE acknowledges that vaping is not risk-free and that its long-term effects remain uncertain. See What the Cochrane living review found, and the sources that argue against us in The evidence library.