(CNN) The U.S. Consumer Product Safety Commission issued a recall Wednesday of 501,000 self-balancing scooters, often called hoverboards, due to fire hazard.
The lithium-ion battery packs in the hoverboards can overheat, resulting in sparking, smoking, fire and explosion, according to the agency. There have been at least 99 incidents of burn injuries and property damage reported.
The commission has investigated more than 60 hoverboard fires in more than 20 states that resulted in more than $2 million in property damage, according to a statement from CPSC Chairman Elliot F. Kaye.
The recalled hoverboards, which have two wheels, were sold between June 2015 and May 2016 at retailer stores and online, including Overstock.com. They are made by 10 companies, manufactured in China and sold at a cost of $350 to $900.
"Let me be clear about this: All of the hoverboard models included in this recall were made with fundamental design flaws that put people at real risk," Kaye said in a statement. "They were made and sold without a safety standard in place."
Consumers are advised to discontinue use of these products and contact the company for information about a refund or, in some cases, a repair. A list of the recalled hoverboards is available from the CPSC.
In December, Kaye told CNN that the agency was working non-stop to figure out what was causing these products to "burst into flames." Around Christmas, the hashtag #hoverboardfail took off on Twitter and Instagram, documenting collisions and crashes among people balancing on the popular two-wheeled devices. In early 2016, in response to fires and falls, Amazon offered full refunds on any hoverboards sold on the website.