One of the propane rubber hoses in a portable generator has cracked and broken in several spots while the other one is in fine condition. As a stop gap a washing machine supply line was cut and used. Is there something about the propane that requires a special kind of material for the hose?
Simple answer - yes, it needs to be rated to supply gas.
If you need guidance, call your local gas company for advice - the good thing is that these pipes aren't expensive, so you'll pick one up for very little.