An electronic cigarette exploded in the face of a man in Albany, New York, recently, leaving him with a hole his tongue and burns on his hand, CNN reported. The explosion also knocked out several of the man's teeth.
But this is far from the first injury caused by an exploding e-cigarette, or e-cig.
The battery-powered devices work by heating a liquid, which typically contains nicotine as well as other chemicals, into a vapor that a user then inhales. But the lithium-ion battery that heats the liquid within an e-cig poses a big safety risk: The batteries have the potential to explode, Dr. Michael Siegel, a tobacco researcher and professor of community health sciences at the Boston University School of Public Health, told Live Science recently. [E-Cigarettes: What Vaping Does to Your Body]
Last month, a teen in New York City was hospitalized after an e-cig exploded while he was testing it out in a store, according to CBS News. The explosion damaged both of the teen's eyes.
And in November 2015, an e-cig explosion left a Tennessee man potentially paralyzed, the Huffington Post reported. The explosion fractured the man's vertebrae and bones in his face, and knocked out a tooth.
In July 2015, a young man in Alabama was airlifted to a hospital and placed on a ventilator after an e-cig blew up in his face. In addition to first-degree burns on his face and chest, the explosion left the young man with a hole in the roof of his mouth that made it difficult for him to eat, according to AOL News.
And earlier last year, a man's exploding e-cig was powerful enough to shatter glass in the Southern California store he was in, NBC Los Angeles reported. After the blast, the man was rushed to the University of California San Diego Burn Center for treatment.
Why e-cigs explode
In a 2014 report, the U.S. Fire Administration examined e-cig explosions between 2009 and 2014. Lithium-ion batteries in other devices such as cellphones and laptops have also been known to cause fires, the report said. But the design of e-cigs – with their cylindrical shape, and the weakest structural point at their ends – makes these devices more likely than others to explode if the battery fails, according to the report.
The fires start in the battery. While all batteries contain electrolyte solutions (this is an essential part of how they work), the solutions used in lithium-ion batteries are different from those in regular batteries because they are flammable, the report said.
In a lithium-ion battery, the solution can become overheated, reach its boiling point and then rapidly expand and catch fire, causing the battery to explode, according to the report. Laptops and other devices have rigid plastic cases that prevent an exploding battery from doing much damage. But in an e-cig, the explosion can lead the cylindrical container of the device to explode, too, causing the device to "be propelled across the room like a bullet or small rocket," the report said.