Imagine we’d found a way to get millions of people to switch from alcohol, which in this country kills 10,000 people a year, to another kind of substance: still addictive, still not risk-free, but when compared with the booze, pretty harmless. Coffee, say.

A public health miracle is hailed. Liver units are empty. Heart surgeons spend more time on the golf course, and costly government prevention programmes close. Millions chink into NHS coffers.

But now, imagine a hitch. Amid all this, a coffee fad has taken hold in schools – every chance they get, kids are slipping off to sip on lattes in a range of disgustingly sweet flavours. Parents worry: caffeine is bad for the developing brain. And then some evidence emerges that a couple of chemicals produced in the roasting process are possible carcinogens – but mostly in far higher doses than in the average coffee cup. Results are not conclusive.

From these seeds, a panic takes hold, and grows. What to do? You make it illegal to sell coffee to under-18s, but children are still getting hold of it. So what next? Drive up coffee taxes? Outlaw advertising? Put coffee in plain packaging? Forbid coffee on trains and in the street? Ban all but the bitterest brands?

Is it really worth risking this public health miracle you have waited so long for?

This is a column about vaping, about which Britain is in a self-sabotaging moral panic. The latest instance of panic showed up in last week’s tobacco and vapes bill, which proposed a ban on vape adverts and sponsorship, as well as powers to restrict flavours, packaging and display. We heard that vaping may be banned in non-smoking areas.

More panic showed up in the budget last month, in the form of an extra tax on vaping liquid. And that followed a panicky announcement that disposable vapes will be outlawed from next summer.

Let us start with how odd it is to be imposing bans on the most popular and effective aid for quitting smoking that we currently have. We take for granted, perhaps, that smoking rates are falling, but it’s still a colossal health problem: about 11% of adults in Britain smoke, and each year it kills about 76,000 of us. It costs the NHS £2.5bn a year – and the country £13bn in lost productivity. It is still the leading cause of preventable death and disease in England.

People know the dangers, but it’s very hard to stop and, for many, vaping is the answer. The quit success rate, when using a vape, is between 60% and 74%. Health charity Action on Smoking and Health finds in its latest survey that, among all who have stopped smoking in the last five years, just over half report they have used a vape to do so. This comes to 2.7 million people.

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Vapes have achieved what decades of government initiatives struggled to do – getting us to give up the cigs

In short, vapes have achieved what decades of government initiatives struggled to do. They are getting us to give up the cigs.

But now this marvel is at risk. Worries about e-cigarettes have infected government departments and the population at large, and smokers are viewing them with suspicion. In fact, more than half of smokers in England now incorrectly believe that vaping is more harmful or as harmful as smoking. It’s not.

So how safe are vapes really? The answer, so far, seems to be “fairly”. They contain nitrosamines, a carcinogenic family of chemicals, but only at “insignificant” levels. Nickel and cadmium, resulting from vape heating elements, are also bad for you, but only at far higher amounts than found in vapes. Neither do vapes cause “popcorn lung”, as some believe – the name for a rare disease called bronchiolitis obliterans, caused by a chemical that is banned in vape fluids.

The main danger in vape fluid seems to come from formaldehyde and acetaldehyde, both known to increase the risk of cancer. But experts agree that this threat is tiny when compared with the damage caused by cigarettes. Cigarette smoke contains about 70 carcinogens, as well as tar and poisons such as carbon monoxide and arsenic. A recent modelling study found that the cancer risk from e-cigarette emissions stood at less than 1% relative to tobacco smoke.

So why do people think vapes are as dangerous as cigarettes? It’s an odd feature of human psychology that we tend to overestimate unfamiliar risks and underestimate familiar ones. We know cigarettes kill us. We are unsure whether vapes might be bad for us in one or two minor ways. Somehow, the messages mix.

There are good reasons to restrict underage vaping. Young brains exposed to nicotine are more likely to become addicted to other things later on. But there are also reasons not to go overboard. Anxious talk of an “epidemic” in schools is overblown: the most recent data tells us that only around 9% of 11- to 15-year-olds vaped frequently in 2023, the same number as in 2021.

It would be better if kids did not vape, but taxing vapes and restricting flavours is not the answer: this risks harming adult smokers who might otherwise be tempted to switch. It is already illegal to sell vapes to under-18s; the rest of the work could be done by schools and parents, the same way we deal with other harmful underage behaviour. Let’s note that rebellious kids have indulged in far more dangerous fads. In fact, if we really want to help children’s health, we could do something about their rising alcohol use, now at record levels in England.

But let’s end with a cautionary tale from Australia, which made vapes prescription-only in 2021. What followed? A low uptake of prescription vapes, and a rise in smoking rates. Our victory over the cancer sticks is more fragile than we might think. Let us not endanger it.

Martha Gill is an Observer columnist