Fire explosions linked to e-cigarettes spark safety concerns

A Kentucky man is recovering from second-degree burns after he says an electronic cigarette battery exploded in his pocket.

Surveillance footage captured the moment Josh Hamilton's pants suddenly burst into flames at a Kentucky gas station Saturday. He runs outside, struggling to ditch his clothes, before a man douses him with a fire extinguisher.

Hamilton posted on Facebook: "Just had an e-cig battery blow up and catch fire inside my pocket! Ouch." This is the latest incident linked to electronic vaporizers across the country, raising new concerns about the multi-billion-dollar industry, especially when it comes to the devices' batteries, reports CBS News correspondent Vinita Nair.

Evan Spahlinger was placed in a medically-induced coma for three days at a Miami hospital, after he says an e-cigarette blew up in his mouth in October.

"There's an alternative to smoking cigarettes. It's supposed to be a safer and a healthier way of doing it," Spahlinger said.

And earlier this week, an Ohio fire department issued a warning on its Facebook page after a rechargeable e-cigarette battery apparently exploded inside the pocket of a victim's lab coat.

According to the U.S. Fire Administration, people reported more than two dozen incidents of explosions and fires caused by e-cigarettes between 2009 and 2014.

"It has the same fuel capability as gasoline," said Venkat Viswanathan, a mechanical engineering professor at Carnegie Mellon University.

Many are linked to the vaporizer's lithium-ion battery. Overcharging, manufacturing defects and punctures can cause it to overheat, triggering an explosion.

Those lithium-ion batteries are the same type found in many hoverboards, which have also been criticized for catching fire.

"In terms of the actual product itself -- that this is the cell chemistry -- you are comparing apples to apples between what happens in the hoverboard and what happens in the e-cigarette," Viswanathan said.

But vaping advocates maintain that reports of explosions from e-cigarettes are rare.

In a statement, the American Vaping Association said: "When charged and used under proper conditions, vapor product batteries pose no more of a fire risk than similar lithium-ion batteries that are used in cell phones and laptops."

The Food and Drug Administration does not regulate e-cigarettes. Industry advocates say users should always use compatible batteries and chargers and avoid battery contact with metal objects such as coins, keys or jewelry.