More than 400,000 Casely wireless phone chargers were recalled Thursday over concerns that they could pose a fire hazard, officials said.

Casely, a company based in the New York City borough of Brooklyn, received 51 reports of lithium-ion batteries inside the power banks overheating, expanding or catching fire while consumers were charging their phones, causing at least six minor burn injuries, the US Consumer Product Safety Commission said in a notice.

Consumers who purchased Casely Power Pods 5000 mAh portable MagSafe wireless phone chargers with model number E33A are urged to stop using them immediately and contact the company for a free replacement.

The roughly 429,200 affected phone chargers have “Casely” engraved on the front and the model number on the back.

The pocket-size power banks were sold at getcasely.com, Amazon and other e-commerce websites from March 2022 to last September, the commission said. Discarded differently, the phone chargers should not be thrown in the trash or recycled in either the general recycling stream or the used-battery boxes commonly found at retail and home improvement stores, the commission said.

That’s because the recalled lithium-ion batteries, which pose a greater fire risk than other batteries, must be discarded differently. Consumers can contact their local household hazardous waste collection centre to see if it accepts recalled lithium-ion batteries. If it does not, the commission recommends contacting local municipal officials for more guidance.

Lithium-ion batteries are rechargeable, last a long time and store a lot of energy in a small space. These features have made them a staple in common devices, including phones, laptops, toothbrushes, power tools and electric vehicles. However, the batteries require safe handling because of their potential to start fires.

The US Fire Administration advises consumers to stop using lithium-ion batteries if they emit an odour, put out too much heat, leak, make odd noises, or change in colour or shape. Before purchasing products, consumers should look for a “Nationally Recognised Testing Laboratory” stamp, according to the fire administration.