I would burn it. While gas IS volatile, it's the fumes, and not the liquid that is. To burn gas safely start the first FIRST and throw the gas on a cup full at a time at the base. You'll get a small woosh but you can do so from a safe distance with no problem at all. If there's oil in it it will be even less of a "woosh". Most people make the mistake of pouring gas on and waiting a few seconds before lighting it. That's when the vapors have a chance to disperse and you get a nice explosion, sometimes a good distance from where you threw the gas, depending on wind. Mixing with oil does a good job of dampening the volatility. (While I expect some "flaming", no pun intended, for my opinion, it CAN be done safely if you use a little common sense!)