Pressurized Gas Tanks
Empty, small 16-ounce propane canisters can be disposed of in the regular trash. To empty a 16-ounce propane canister, it must be used on a grill, lantern or other device until the device turns off because there is no fuel left in the canister.
Full-sized (20 pounds or larger) pressurized tanks that contain flammable gases such as propane or helium cannot be disposed of in your regular trash due to risk of explosion and fire. If the tank is completely empty and the pressure valve has been removed, contact a local scrap metal recycling facility to ask if they will accept it.
If a full-sized gas tank still contains a pressure valve, there are several local businesses that will accept it to refill or recycle. Below is a list of these facilities. Before delivering any materials to these businesses, always call ahead to make sure they are still accepting the material you wish to dispose of and find out if there are any associated fees.