Elisha G. Brownson, M.D., a burn and trauma physician, saw her first victim of an exploding e-cigarette after he was wheeled into the ER in Seattle. The device had burst into flames in his mouth while he was driving. “He was bleeding so severely that emergency workers had to insert a breathing tube into his throat before transporting him by ambulance,” Brownson says.

The man was just one of 15 patients with similar injuries that Brownson and her colleagues treated between October 2015 and June 2016, which is described in a new issue of the New England Journal of Medicine. “We believe these injuries are far more common than most people realize,” she says.

Another report in the same issue of the journal reviews what’s known about other risks posed by e-cigs, ranging from inhaling potentially dangerous chemicals to concerns about whether the devices actually help people quit smoking, and whether they introduce young people to nicotine and then regular tobacco cigarettes.

Risk of Explosions

E-cigarette explosions were once thought to be rare. For example, the U.S. Fire Administration, a branch of the Federal Emergency Management Agency, found that only 25 explosions involving e-cigs were reported in the U.S. media between January 2009 and August 2014, and just nine resulted in injuries. And a Consumer Reports Freedom of Information Act request to the Food and Drug Administration revealed just four reports of exploding e-cigarettes between the end of 2006 and November 2013.

But Brownson, who trained at Seattle's UW Medicine Regional Burn Center at Harborview and is now a general surgeon in Anchorage, Alaska, says that her experience suggests that e-cigs injuries are far more common.

“We definitely think that the numbers are underreported,” she says. “In 2016 we have consistently seen an average of two patients a month.”

The injuries can be serious, including flame burns, chemical burns, and blast injuries, mostly to the face, hands, thighs, and groin. Many require complex care involving emergency medicine personnel, plastic surgeons, burn care providers, and even vocational counselors and psychologists. Brownson’s first patient, for example, spent two days in the ICU as oral surgeons repaired his broken and missing teeth and stitched his lip, she says. Another required multiple surgeries to remove debris in his hand and other injuries that had caused severe infection.

One reason the injuries are so severe: E-cigarettes are more likely to behave like “flaming rockets” when a battery fails, as opposed to other products with lithium-ion batteries, according to the Fire Administration.

That effect stems from the devices’ shape and construction, explains Consumer Reports’ senior product tester Bernard Deitrick.

“An e-cigarette is basically a metal tube designed to allow air to flow from one end to the other,” he says. “When its battery fails catastrophically, the tube becomes a guide for the combustion products from the battery, forcefully propelling them toward the ends as the device breaks apart.”

Gregory Conley, president of the e-cigarette advocacy group American Vaping Association, says that e-cigs when used properly are no more dangerous than other items powered with lithium-ion batteries, such as cellphones and laptops.

But, he acknowledges, "when vapor products are subjected to extreme conditions or used with unwrapped or damaged batteries, short circuits can occur. Whether it's the batteries intended for use in a flashlight or a vapor product, carrying batteries unprotected is a terrible idea. Most vape shops now carry battery cases and some provide them for free or refuse to sell loose batteries to those who don't have a case."

Still, Brownson worries that e-cigs may pose unique concerns. “As a burn and trauma surgeon, I absolutely wouldn’t let my kids use these and I wouldn’t let them in my house,” she says.

William Wallace, policy analyst for Consumers Union, the policy and mobilization arm of Consumer Reports, is also concerned.

"The battery systems for these devices should be safe, just as the batteries for smartphones or laptops or hoverboards should be safe. Companies must design, build, and test e-cigarettes to minimize the risk of fire, and the government must protect the public through stronger regulation of the e-cigarette marketplace," he says.

A vape device (on right) plus its batteries after it exploded, sending a 2-year-old boy to the UW Medicine Regional Burn Center in Seattle for treatment.
Photo: UW Medicine Regional Burn Center

Other Dangers

The second article in the recent issue of the New England Journal of Medicine, co-authored by Chitra Dinakar, M.D., a professor of pediatrics at the University of Missouri-Kansas City, evaluates the evidence and research into the health effects of e-cigs.

Unlike tobacco cigarettes, which are better understood because they have been studied for years, there is still much we don’t know about e-cigarettes, says Dinakar, who is also an asthma and allergy specialist at Children's Mercy Hospital in Kansas City, Mo. E-cigs may be less harmful than traditional cigarettes, and thus a better choice for smokers, but with limited evidence and so many uncertainties, she says, “We just don’t know,” adding, "There are many unexplored potential toxic effects that need further study.”

Here are some of the areas of greatest concern:  

• The vapor may contain harmful chemicals. E-cig liquids typically contain a base of vegetable glycerine or propylene glycol. These substances are considered safe to eat, but, Dinakar says, that doesn't necessarily mean they are also safe to inhale. “Heating a chemical can also cause it to change into something that is potentially harmful,” Dinakar says.

For example, a study out earlier this year found 31 different chemicals in e-vapor, many of them possible or probable carcinogens. Most were traced back to the vegetable glycerine or propylene glycol and released when the chemicals were heated.

In addition, e-cigarette liquid often contains an array of flavorings. Those ingredients are commonly used in foods as additives, Dinakar says, “But again, they may not be safe to inhale.”

For example, sweet-flavored e-cig liquid often contains diacetyl or acetyl propionyl, chemicals used to create the buttery flavor in foods such as microwave popcorn. While approved for use in foods, they have been associated with respiratory disease when inhaled, for example by workers manufacturing products.

And e-cig liquids have been found to contain varying amounts of a number of chemicals, many of which may not have been studied. According to a 2014 article in the journal Tobacco Control, there were 7,764 unique flavors of e-cigarettes available for sale in 2014.

In addition, studies in mice suggest that e-cig vapor may cause lung inflammation, according to Dinakar's research. And another study she cites found that mice that were exposed to e-cigarette aerosol and injected with influenza virus had higher rates of illness and death than the unexposed mice. 

Conley of the American Vaping Association, says, "Public Health England and the Royal College of Physicians have both released extensive reports estimating vaping to be at least 95 percent less hazardous than smoking."

• E-cigs may introduce teens to nicotine and regular cigarettes. E-cigarettes are particularly appealing to young people, Dinakar says. In 2015, the Centers for Disease Control and Prevention reported that 16 percent of high schoolers and 5 percent of middle schoolers had tried vaping. Worryingly, recent studies show that high schoolers who vape may be more likely to take up smoking tobacco cigarettes—a habit that leads to myriad health problems including an increased risk for cancer and heart disease.

Moreover, the nicotine itself can pose dangers. “Many e-cigs also contain nicotine, which we know is addictive,” Dinakar says.

Not only can nicotine stunt cognitive development, but it is also considered a gateway drug. “In teenagers, nicotine impacts the brain in a way that makes them more predisposed to trying drugs, increasing their susceptibility to dependence on marijuana, cocaine, and other illicit drugs,” she says. 

• E-cigs may not help you quit smoking. E-cigarettes are often touted as an effective smoking cessation device, and they may well help some people quit. But Dinakar says that there isn’t enough information from randomized trials to know for sure.

For example, the largest clinical trial to date—a study of 657 smokers in New Zealand—found that after six months the difference in quit rates between people who used nicotine e-cigs, non-nicotine e-cigs and nicotine patches were not statistically different. Overall, 7.3 percent of those who used nicotine e-cigarettes had quit, 5.8 percent of those who used nicotine patches had quit, and 4.1 percent of those who used non-nicotine e-cigarettes had quit.

The trial also found that about one third of the participants continued to use both tobacco and e-cigarettes.

Bottom line: Marvin M. Lipman, M.D., Consumer Reports chief medical adviser, says that with so many uncertainties about the safety of e-cigarettes and the real risk of suffering injuries from an exploding device, adults should use the devices with great caution, if at all.

And teens should not use the devices. In fact, as of last summer, retailers are no longer allowed to sell them to people under the age of 18. "If you see a teen vaping," Lipman says, "remind them of these serious and potentially disfiguring risks."