If Holger did not mean to address the relative hazards of vaping and smoking, it is confusing, to say the least, that he opens the original article with this question: “Are e-cigarettes really any better than smoking a cigarette?” More to the point, an article about the potential health hazards of vaping that fails to talk about how those hazards compare to the well-established risks posed by smoking is irresponsible, especially since regular users of e-cigarettes consist mainly of current or former smokers.

For a smoker contemplating a switch to vaping, it is worse than unhelpful to say, as Holger does, that “e-cigarettes pose dangers to our health,” that they “carry their fair share of toxic chemicals,” or that they “have negative effects on lungs.” The relevant question is how the risks of vaping compare to the risks of smoking, and there is no question that they are much lower. By implying otherwise, e-cigarette alarmists may very well deter smokers from making a switch that could save their lives.

Holger claims to be agnostic on the question of whether vaping is safer than smoking, and he thinks this is a scientific position. It isn’t.

“Sullum is right that I had no intention of answering this question,” he says in his reply. “I don’t have the answer because the jury is still out. It could potentially take decades of research before we know the long-term effects of e-cigarettes compared to smoking.”

This seemingly cautious position is not only wrong but reckless. We already know, based on the fact that e-cigarettes do not burn tobacco or anything else, coupled with chemical analyses of the aerosol they produce, that they are much less dangerous than conventional cigarettes. According to what Public Health England (PHE) calls the “best estimate” of the difference in risk, vaping is about 95 percent safer than smoking.

Holger is unimpressed. “Even if e-cigarettes are ‘95% less harmful’ than cigarettes,” he says, “that doesn’t mean they are safe.” In a world where nothing is 100 percent safe, this mindless insistence on the complete elimination of risk is a menace to public health. An alternative to smoking that’s 95 percent safer is a huge opportunity that should be welcomed by anyone who wants to reduce tobacco-related harm.

Might the current estimate of the difference in risk be off by a few percentage points? Sure. That’s why it’s called an estimate. But such a correction would not affect the conclusion that smokers who switch to vaping dramatically reduce the health risks they face. That would still be true even if the estimate exaggerated the difference by a factor of two, although there is no reason to think it does. In fact, it’s possible that the actual risk reduction is higher than 95 percent. “Some flavourings and constituents in e-cigarettes may pose risks over the long term,” says Ann McNeill, co-author of the PHE report. “We consider the 5% residual risk to be a cautious estimate allowing for this uncertainty.”

It is true that we don’t know exactly what the long-term health effects of vaping are. Although propylene glycol and vegetable glyercin, the main components of e-cigarette “vapor,” are approved as safe food and drug ingredients, a widespread practice of inhaling aerosols containing these substances is relatively new. But contrary to what Holger implies, that does not mean we need “decades of research” to know whether smoking is more dangerous than vaping. Whatever the long-term effects of inhaling propylene glycol or glyercin, they cannot possibly compare to the long-term effects of inhaling the numerous toxins and carcinogens in tobacco smoke. Hence it is journalistic, medical, and public health malpractice to tell a smoker who is thinking about trying e-cigarettes that he should wait a few decades until the evidence is clearer.