Perishables and Experimental Drugs

On a Delta Airlines flight, I noticed a label on the life raft, which said "Expendables expiration date", where I would have expected "Perishables expiration date". Apparently, we aren't allowed to say "perish" in connection with an airplane (but we are allowed to say "expire").

I've also heard radio ads for research organizations looking for subjects talk about "investigational medications," which used to be called "experimental drugs."