Scenario (and a bit of a trick question):
you are on a commercial flight at 38,000 ft
Since it is an Airbus, there is a computer glitch.
First, the cabin is fully depressurized. Your eardrums burst.
Fortunately, the wimpy oxygen mask pops down. You start inhaling O2, lets say for the sake of the arguement that you get an-impossible-with-that-rig 100%.
Then, the pilot announces that the computer prevents the plane from descending and you stuck at 38,000 ft over the Pacific Ocean, but there is enough fuel and oxygen for 6hrs by which time the problem will be fixed.
Can you live at 38,000 ft with inspired 100% O2?