Do you want to enjoy the outdoors and help the environment at the same time? The makers of the Jet Boil cooking system with their “Crunch it” tool make it easy. Simply drain your fuel canister of any remaining gas and then punch a few holes in the cylinder. This lets the folks know at recycling center that your canister is completely empty, thus it can be recycled. When using Coleman brand tanks, use their Green Key system for the same purpose.