10 years isn't a minimum threshold for every item. Any individual item could fail any time, and the overall distribution will have a shape somewhere between a

10 years isn't a minimum threshold for every item. Any individual item could fail any time, and the overall distribution will have a shape somewhere between a bell curve and a long tail. I don't know if there are any regulations around the 10-year claim, but if there are then I'd expect that it's either an average or something like a one-standard-deviation threshold, like 68% last past that but 32% don't. "Guaranteed 10 years" doesn't actually say anything about expected lifetime at all, just that they'll do a warranty replacement if it fails sooner.