The United States Postal Service is the latest company to crack down on hoverboards, with a spokesperson telling CNET that they have banned all hoverboard shipments by air transportation "effective immediately and until further notice". The changes mean that USPS will only ship the devices via Standard Post or Parcel Select, which use ground transportation.

The reason why USPS has banned air shipments of hoverboards relates to their large lithium batteries. The volatile nature of these batteries poses a safety hazard while in the air, and considering there have been some reports that hoverboard batteries have caught fire or exploded, shipping companies like USPS are taking no risks in their transportation.

Some of the safety concerns have arisen due to the widespread availability of cheap Chinese hoverboards, which are manufactured without the same quality standards as known brands like Swagway and Razor. These cheap boards don't necessarily contain the same critical battery circuitry as their more expensive equivalents, which can lead to unregulated battery output, fires, and explosions.

One particular hoverboard produced by RioRand is known to be unsafe, and companies that sold the product, such as Amazon, have advised customers to throw them out to receive a full refund.

USPS isn't the only company to crack down on hoverboards. Delta, United and American Airlines all banned hoverboards as both carry-on and checked luggage last week, while Amazon has started to remove listings for the self-balancing two-wheeled boards over similar safety concerns. Another retailer, Overstock, refuses to sell them at all.