The SCH 40 I’ve seen has always explicitly said not to use with compressed air.
Here is the issue - Plastics like polycarbonate flow or melt when stressed. PVC cracks and breaks into pieces when stressed. That means when the 10 year old piping you have gets hit by an errant ski pole, or other object, it’s not just going start leaking air, it may literally explode, posing a risk of injury.
Air compresses a lot and when the pipe starts to yield, the air pressure doesn’t drop as soon as some air starts to leak. So as the initial crack propagates down the pipe at great speed, and the air pressure maintains, you end up with a bang that has lots of high speed plastic flying around your basement.
Water on the other hand doesn’t compress much compared to air so if the pipe starts to yield (at the same pressure as it would with air) and water starts leaking, the pressure drops very rapidly at the source of the leak. This pressure drop at the crack means the cracking progresses much slower and there is very little high speed plastic (none really).
It’s the same reason that a balloon filled with air goes BANG when popped, and one filled with water just gets you wet when popped. Now amplify that effect by a 100 to get a feel for the difference bewteen 150PSI of air, and 150PSI of water.