Ask an Expert: Are e-cigarettes 'safe'?

Tom Gross, MD

Electronic cigarettes are a multi-billion-dollar industry in the United States—one that spends tens of millions to advertise to teenagers and young adults, according to a U.S. Surgeon General’s report released in December 2016.

But aren’t e-cigarettes a less harmful alternative to traditional cigarettes? We asked University of Iowa Health Care pulmonologist Thomas J. Gross, MD, to help clear the air.

How do e-cigarettes work? And what is vaping?

An e-cigarette is made up of four basic parts: a battery; a heating element that heats up a liquid-filled cartridge to produce an aerosol, or vapor; and a mouthpiece, or tip, used to inhale the vapor. The liquid typically contains nicotine, additives, and flavorings—coconut, chocolate, or fruit, for example. Vaping is the act of inhaling and exhaling the vapor, just like smoking a cigarette.

E-cigarettes contain nicotine?

Nicotine-free liquids are available, but the majority of vaping liquids do contain nicotine. That’s the basic purpose of an e-cigarette—it’s a nicotine delivery device. At present, all major-market e-cigarettes contain tobacco-derived nicotine. So, if it contains nicotine, it’s essentially a tobacco product.

What about the flavorings?

The ingredients they put in e-cigarettes beyond the nicotine itself—the flavoring agents and the agent that makes the actual visible “smoke”—are all FDA-approved, food-grade chemicals. So presumably they’re safe if you were to drink them. But no one really knows if it’s safe to “burn” these and inhale the product. There isn’t enough data yet to know for sure.

However, we do know that some of these chemicals used in e-cigarettes have been dangerous in other settings. Take diacetyl, for example. This chemical was used as a popcorn flavoring, until we learned that diacetyl was linked to bronchiolitis obliterans, which is also known as popcorn lung. It’s a serious condition where you have scarring of the tiny airways in your lungs. Again, no one has definitively demonstrated that e-cigarettes cause popcorn lung, but we’re talking about the same chemical.

The agent used to create the “smoke” effect in an e-cigarette typically is propylene glycol or some glycol derivative. This is the same sort of stuff they use in fog machines at entertainment venues, and there have been cases of performers having allergic reactions or lung irritation from long-term passive exposure in these settings. Now think about repeatedly inhaling this chemical in an e-cigarette. There’s reason to be concerned, although again not proven yet.

Are e-cigarettes “stop-smoking” tools?

Some people argue that e-cigarettes will help a person quit smoking, but there’s really no evidence for that. The success rate of quitting smoking using e-cigarettes is no higher than with other nicotine replacement aids and is no more durable.

But e-cigarettes aren’t marketed as medical aids. They’re marketed as a surrogate for smoking. And most e-cigarettes contain nicotine, which is addictive. Nicotine is bad for your heart, it raises your blood pressure, and it can increase your risk of stroke or heart attack.

So, people aren’t helping themselves by switching to e-cigarettes?

Let me put it this way: I do believe e-cigarettes are less toxic than regular cigarettes. However, I do not believe they’re non-toxic. And nothing beats not smoking or vaping at all.

Last reviewed: 
April 2017

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