Hoverboard Safety Fears Grow as Problems Mount

So-called hoverboards, the two-wheeled, gliding motorised scooters that have taken over side-walks and social media in recent months, are coming under greater scrutiny after reports of fires and explosions.

With the fad growing and people getting hurt, some online retailers are removing the products from their sites, and the federal Consumer Product Safety Commission is rushing to investigate as the Christmas shopping season rolls on.

The commission has logged 29 emergency room visits and 11 reports of fires in 10 states, said Elliot F. Kaye, chairman of the commission, in an interview Monday.

"We're particularly sensitive to the fact that many have been purchased and wrapped," he said.

The self-balancing boards do not actually hover or fly, but they go fast enough to attract trouble. Officials have banned the troublesome toys from city sidewalks and from airplanes, and fire marshals across the United States are issuing warnings against them amid stories of fires and explosions.

A home in Lafitte, Louisiana, was badly damaged in November after one of the electric scooters caught fire while being recharged. This month, the battery pack on one of the gadgets appeared to catch fire as a man rode it down a sidewalk in Alabama. And, last week, a scooter caught fire in a mall in Washington state as holiday shoppers watched.

Meanwhile, some online retailers, like Overstock, have decided to stop selling the electric scooters altogether. Amazon is reportedly pulling e-listings for some of the boards from its virtual shelves. Some top-rated hoverboards are now missing from the site, and one manufacturer told The Verge that the toys were subject to an Amazon safety review. Amazon did not respond to a request for comment Monday.

But consumers can still easily find hoverboards for sale direct from several manufacturers and big-box retailers, and from a few remaining listings on Amazon. ("It doesn't start fire," reads one of the reviews on a model still for sale.)

Chinese companies manufacturing and selling budget models on eBay and elsewhere are a particular area of concern, Kaye said. But the fact that many of the problematic toys are coming from the same part of the world may be a good thing in this case.

"I think my hope would be it would at least allow us to feel like we discovered the universe of these products," he said. "On the back end, certainly we would want to work with the Chinese government."

A leading indicator of the fires appears to be the unpredictable lithium-ion batteries found inside the devices, Kaye said. Since the toys are unregulated, several companies are using different manufacturing techniques in order to make a generic model. This helps those companies avoid any intellectual property inquiries as they are shipped overseas to US consumers, Kaye said.

"They don't all look the same inside," Kaye said of the problematic models. "It looks like there might be overcharging, too many batteries stacked together in ways that lithium-ion batteries are not meant to be stacked."

Lithium-ion batteries are versatile and lightweight enough to be used in a variety of electronics, including laptops and cellphones, but the hazards of packing so much energy into a compact battery has its drawbacks. Poorly designed batteries can overheat and are prone to explosion. But, as Wired reported, there is no guarantee that even high-quality batteries won't catch fire, which means it will not be easy for consumers to safeguard against hoverboard fires.

"There is no way to tell when buying, since the catastrophic failure likely will not manifest until the battery is fully charged and discharged several times," Jay Whitacre, professor of materials science and engineering at Carnegie Mellon University, told Wired. "This charging/ discharging mechanically exercises the guts of the cell and typically provides the ultimate trigger for the failure."

Kaye said that investigators have seen at least five different battery configurations in the samples they are studying, but added that the unpredictable nature of the batteries means that the samples must be shipped in special containers, which slows down the process and reduces the number of samples that can be studied while investigators rush to turn around a report in time for Christmas. The lack of consumer regulation is frustrating to officials, who often do not get involved with new products like hoverboards until injuries or deaths are reported.

"People just put it out there," Kaye said, "and then we're left to pick up the pieces once the injuries start mounting."

Because the toys are unregulated, basic guidance on how to buy a safe hoverboard is scant. The National Association of Fire Marshals recommends that consumers avoid leaving the devices unattended while they charge, and that they let the devices cool off before recharging them.

© 2015 New York Times News Service