In what might be the biggest smartphone recall ever, Samsung has halted sales of some 2.5 million new Galaxy Note 7 smartphones, amid ongoing reports that a flaw in the device's batteries is making them catch fire and explode.

Adding to the controversy, the FAA might also ban them on planes, meaning travellers will be prohibited from taking a potentially faulty Note 7 on board aircraft in the US.

Last week, Samsung announced that it had voluntarily initiated its own product recall, but if it elects to institute a formal process with the US Consumer Product Safety Commission, the FAA would have to enact the ban.

"If the device is [formally] recalled by the manufacturer, airline crew and passengers will not be able to bring recalled batteries or electronics that contain recalled batteries in the cabin of an aircraft, or in carry-on and checked baggage," an FAA spokesperson told Matt Novak at Gizmodo.

The South Korean electronics company delayed shipments of the smartphone last week, after several people posted images online of burnt, broken Note 7s. It then announced a recall of all 2.5 million devices on Friday.

"[As of September 1], there have been 35 cases that have been reported globally, and we are currently conducting a thorough inspection with our suppliers to identify possible affected batteries in the market," the company announced in a statement. "However, because our customers' safety is an absolute priority at Samsung, we have stopped sales of the Galaxy Note 7."

Samsung says it has conducted a "thorough investigation" of the issue, and claims the flaw stems from a problem with the Note 7's battery cell. Due to an undisclosed manufacturing defect, the lithium ion battery cell can overheat when charging, leading in some instances to the battery catching fire or exploding.

We've seen this issue flare up before with devices like ride-on 'hoverboards', leading to many airlines and aviation authorities around the world banning them on planes last year after a series of dangerous incidents.

"If there is an inherent defect in the cell, it will go off at some point," materials scientist Jay Whitacre from Carnegie Mellon University told Wired at the time.

"Small defects in the manufacturing or materials stream lead to the plus/minus sides of the batteries being shorted with each other after a small amount of use. When this happens, especially when the batteries are charged, a lot of heat is generated inside the cells and this leads to electrolyte boiling, the rupture of the cell casing, and then a significant fire."

While the amount of Galaxy Note 7s that are considered to be at risk is ultimately small – it's estimated that only 24 out of every 1 million phones are affected – Samsung has no option but to recall every device manufactured in the interests of safety.

"Products installed with the problematic battery account for less than 0.1 percent of the entire volume sold," a Samsung spokesperson told the media last week. "The problem can be simply resolved by changing the battery, but we'll come up with convincing measures for our consumers."

Those measures will differ in every region, but in the US at least, Samsung is offering a product exchange program. Galaxy Note 7 owners can swap their faulty device for a new model (expected to become available in the next week or so), or receive an S7 or Edge smartphone instead.

In the meantime, if you're the owner of a Galaxy Note 7, it'd be advisable not to use the device, and look into organising your replacement as soon as possible. Several US carriers have released their own recall information for their customers.

With Samsung estimated to have already sold around 1 million Galaxy Note 7s since the smartphone was released just last month, it's a major headache for consumers affected by the recall.

And for the company itself too – especially with arch-rival Apple set to announce the iPhone 7 in the next 24 hours.

Nobody knows just how big the fallout will be from this – either financially, or in terms of consumer sentiment – but recalling more than 2 million phones isn't going to be quick, fun, or painless.

But, really, the best we can hope for in this kind of situation is that nobody gets seriously injured or killed while the faulty devices remain in use.

Speaking to media last week, Samsung's smartphone chief, Koh Dong-jin, was clearly unhappy about the problem – one which may ultimately end up costing the company several billion dollars to fix.

"I can't comment on exactly how much the cost will be," he said, "but it pains my heart that it will be such a big number."