If it was, it must be a high-pressure tank for it to survive re-entry and not deform on impact.
If from a ‘dead satellite’ the liquid propellant inside might have frozen solid. That was the problem that NASA feared a few years back. The USN tricked up a Standard-3 missile and shot the thing down so that it would splash in the Pacific where it would be less of a threat.
LOX and LOH tanks are usually high grade stainless or nickel based alloys. High temp resistance as well as structural stability at low temps. That being said don’t crack them open.. Blobs, Green Slime, or decepticons oh my.