A new study led by Dr. Gary Vercruysse points to the failure of lithium ion batteries as the culprit.
Dr. Gary Vercruysse and his colleagues noticed something strange going on in their emergency room about a year and a half ago. It all started when a 58–year–old man with severe burns to his left thigh arrived at Banner – University Medical Center Tucson for treatment.

A few weeks later, a 20–year–old man with severe burns to his right thigh arrived at the hospital's emergency room for care. Not long after that, a third man, this one 37 years old, came in with a severe burn to his left thigh and buttocks.

That's when Vercruysse, a burn surgeon, started to ask those patients and ones with similar wounds how they got burned.

"They all told me basically the same thing," he says. "They had an electronic cigarette in their pocket, then they started feeling a lot of heat in their pocket, and then they couldn't get their pants off or get the device out of their pocket quickly enough."

Vercruysse says he then started perusing the medical literature and noticed that no one had written about the topic previously. So he and his colleagues decided to write a case report describing the initial three patients they had treated for e–cigarette burns.

Their study appeared in the May issue of the journal Burns and points to lithium ion battery failure as the culprit.

"These cases are among the first recognizing thermal injuries sustained from the lithium ion batteries contained in electronic cigarettes, which means there's a need for increased awareness of the safety hazards associated with e–cigarettes," Vercruysse says.

"Since then, we've seen several patients, and only one hasn't gotten a skin graft," he says.

The researchers' study comes at a time of increasing scrutiny of lithium ion batteries contained in so–called electronic nicotine delivery systems, or ENDS, which include electronic cigarettes. In April, the Navy suspended the use, possession and storage of ENDS aboard ships, submarines, aircraft, boats, craft and heavy equipment. And the U.S. Food and Drug Administration and the Center for Tobacco Products hosted a science–based public workshop on April 19 and 20 in Silver Springs, Maryland, to gather information and stimulate discussion about these batteries.

The severity of a burn, Vercruysse explains, depends on the thickness of a particular area and how many calories of heat come into contact with the skin (and for how long).

"So you can have a relatively small number of calories contact you for a long time, and you get a burn, or you can have a relatively large number of calories contact you for a relatively short time and you get a burn," Vercruysse says. "With these cases, there were relatively a lot of calories and the skin isn't that thick, so you get a bad burn."

In fact, the paper describes what is known as "thermal runaway," caused by thermal, mechanical or electrical damage to the battery. No matter the cause of the damage to the battery, once it is damaged, its internal temperature can rise uncontrollably. And once the internal temperature rises, the heated lithium vaporizes and decomposes, releasing gaseous lithium within the battery and increasing its internal pressure. The increasing internal pressure, in turn, can cause the electrolytic component to ignite, resulting in an explosion or fire.

"I think in general the public thinks that e–cigarettes are somehow better for you than tobacco cigarettes, but they still deliver nicotine, which isn't good for you, and this particular product has a defect where the battery can malfunction," Vercruysse says.