The government is launching a new campaign to try to convince the UK’s smokers that vaping is not as harmful as smoking and a good way to quit, in a bid to counter the scepticism generated by some scientific studies and media headlines.

Public Health England (PHE), which maintains that vaping is 95% less harmful than tobacco, is releasing a short video of an experiment which reveals the amount of sticky black tar that accumulates in the lungs of a heavy smoker, collected in a bell jar. By contrast, the same nicotine intake through vaping releases only a trace of residue.

“It would be tragic if thousands of smokers who could quit with the help of an e-cigarette are being put off due to false fears about safety,” said Prof John Newton, director of health improvement at PHE.

“We need to reassure smokers that switching to an e-cigarette would be much less harmful than smoking. This demonstration highlights the devastating harms caused by every cigarette and helps people see that vaping is likely to pose only a fraction of the risk.”

I’ve started vaping and it’s the most millennial – and mystifying – thing I’ve ever done | Ahir Shah Read more

Play Video 2:43 The difference in effects caused by smoking and vaping – video

PHE says the risks from vaping are tiny compared to smoking. Some studies that have been published focus on the risks without looking at those of cigarettes. A lab study from Birmingham University in August, for instance, claimed that vaping could harm cells in the lungs. While the authors said they did not believe e-cigarettes were more harmful than ordinary cigarettes, they suggested that over 20 or 30 years there might be an effect and urged “cautious scepticism” about the safety of vaping.

Martin Dockrell, head of the tobacco control programme at PHE, said all the scientists in the field had ambitions to improve health. “We like to think of our scientists as being detached about these things, but in fact the scientists involved in this area on both sides are deeply passionate about it,” he said.

Studies about the risks of chemicals in e-cigarettes run prominently in the media. Some were misleading and others were contradictory, said Dockrell. “People don’t know who to believe and they believe the thing that suits them best,” he said. A smoker who finds it hard to quit may not want to believe that e-cigarettes are far less harmful.

Facebook Twitter Pinterest People smoking cigarettes. Photograph: Kyodo News/Kyodo News via Getty Images

One of the stories that does the rounds is that vaping causes “popcorn lung” – a condition that makes people cough and struggle for breath which can be caused by a chemical used to flavour popcorn that is also found in e-cigarettes. But the chemical, diacetyl, is also found in ordinary cigarettes at levels 100 times higher.

Concern about e-cigarettes is high in the United States, where vaping has taken off among school students. Many use a small device called Juul, the size of a USB stick. Anti-tobacco campaigners are alarmed that e-cigarettes will be a “gateway” to smoking, and some studies suggest this could happen.

A survey in December by the National Institute on Drug Abuse found a big jump in the numbers of teenagers who were vaping. More than one in three high school seniors said they vaped last year, which was 10 times the number who smoked cigarettes and a 10% increase in a year. A few months earlier, the Food and Drug Administration launched an information campaign to warn young people that there were risks to vaping.

What's leading more teens to try vaping? Study finds 'alarming' rise Read more

PHE says that although e-cigarette use did rise among young people in England up to 2015, the numbers have flattened off since. Unlike the US, the UK has tight regulations, it says, and a limit on the nicotine level in e-cigarettes – which is higher in Juul in the US than it is in the UK. “There are no studies that show vaping increases tobacco use among young people in the UK,” said Dockrell.

PHE says that e-cigarettes could help many more people quit smoking – which kills half of those who take it up. Data from its smoking cessation programme showed that 65%–68% of people who used e-cigarettes as well as nicotine replacement therapies succeeded in quitting.

“We want to encourage more smokers to try and quit completely with the help of an e-cigarette, or by using other nicotine replacement such as patches or gum, as this will significantly improve their chances of success. If you’re trying to stop smoking, our free online personal quit plan will help you find the support that’s right for you,” said Newton.

Dr Lion Shahab, from University College London, who appears in the video, said: “The false belief that vaping is as harmful as smoking could be preventing thousands of smokers from switching to e-cigarettes to help them quit.

“I hope this illustrative experiment helps people see the huge damage caused by smoking that could be avoided by switching to an e-cigarette. Research we and others have conducted shows that vaping is much less harmful than smoking and that using e-cigarettes on a long-term basis is relatively safe, similar to using licensed nicotine products, like nicotine patches or gum. Using e-cigarettes or nicotine replacement such as patches or gum will boost your chances of quitting successfully.”

• This article was amended on 28 December 2018 to more accurately reflect Public Health England’s advice on the safety of vaping.