is this Copper safe to use?

[SloppyJoe]

I was going to make a parrot beak and found a couple feet of 1/4" copper tubing in my basement. It was here when I bought the place and have no idea what, if anything, has been passed through it. If anything had been run through it I'd say it was either heating oil or water.. I'm going to assume the worst and say it was heating oil... Is it safe to use? if not is there anything I can do to it to make it safe? It would be awesome if I could use it.. I wouldn't have to buy 5' of the stuff for just a small bit that I need.

Thanks