The march against potentially unsafe hoverboards continued in Chicago this week, where U.S. Customs and Border Protection officials seized more than 16,000 motorized scooters bearing unauthorized trademark logos.

Officers found that the devices posed a health risk, reports the Chicago Tribune. Many came from China and had false safety marks of approval from Underwriters Laboratories, a company that tests products for safety and certification. Thus far, UL has not approved any hoverboard brand or model as certified safe. Some scooters also had fake Samsung logos.

Seeing those fake UL markings gives consumers “false sense of security,” William Ferrara, director of field operations for the Chicago Customs and Border Protection office said at a news conference Wednesday.

“The batteries do not meet safety standards, and the chargers as well,” Ferrara said at a news conference Wednesday. Some chargers don’t shut off automatically when the lithium batters are charged up, which could lead to an explosion.

Some hoverboards were found in an ocean container, while others were seized from air shipments, he added, with several shippers and importers involved. That number of 16,000 is expected to rise in the coming weeks due to the massive amount of shipments still being processed.

“Due to the work of our officers and import specialists, word got around the smuggling community,” and shipments to Chicago have stopped, he said. Those counterfeit scooters will now be destroyed, he says.

Officials suggest looking at a hoverboard’s power adapter before buying it — if it has a UL mark, note the file number and search for it on UL’s online certifications directory. You should also check to make sure the battery pack is well-anchored.

UL recently accused hoverboard manufacturer Swagway of violating its trademark, by putting the UL mark on its products. Again, UL hasn’t certified any hoverboards for safety whatsoever, the company says.

The U.S. Consumer Product Safety Commission is currently investigating 13 hoverboard companies for safety issues, as well as looking into reports of fires related to hoverboards in 19 states.

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