Propane tank retailers take back refillable 20# tanks.
Many of our Member Towns accept propane tanks at their transfer stations and recycling centers. Keep valve closed: propane is heavier than air. An 'empty' tank will have some residual gas that can be recovered by the propane tank processor.
1 lb. propane tanks can be refilled from a larger tank with a propane tank refill adaptor.
If a 1 lb. tank is EMPTY, remove the valve and plasce in trash or bring to a scrap metal dealer.
Helium and CO2 are chemically inert, so the valves of unwanted tanks should be opened to relieve the pressure. If your town accepts scrap metal, heluim and CO2 tanks may be brought to your town's scrap metal bin, or to a scrap metal dealer.
Propane, ethylene, oxygen and other pressurized flammable gas cylinders are generally not accepted with scrap metal or at haz waste collections. Contact your local fire department for instructions on their proper disposal.