I have a small propane canister that has been accidently hooked up to this little Coleman stove for an extended period of time. I was just cleaning out the garage, and discovered it. I unscrewed the canister from the stove to put it away, and the canister started hissing, so I screwed it back on and the hissing stopped. When I lit the stove to use up the gas that is in the canister, the hissing returned and seemed to get louder over the next minute or so. Is the hissing when the stove is lit because the level of propane is low? Or is there too much propane being delivered to the stove because of the leak? Is this a danger if I light it to dispose of the gas that is in the canister, or is there a better way of safely disposing of this propane canister?

Thanks in advance!