These items contain refrigerant gasses (Freon) and the gasses must be removed by a licensed technician, per the US EPA:
Air Conditioner, Dehumidifier, Freezer, Refrigerator, Water Cooler
These items do not contain refrigerant and can be recycled as scrap metal: Dishwasher, Dryer, Microwave, Stove, Trash Compactor, Washer, Water Heater.
Disposal is available to all District residents at the Clean Sweep Collection or Greenfield Transfer Station. Metal appliances may be taken to WTE Metal Recycler, 75 Southern Ave, Greenfield, 413-772-2200. Disposal options within towns varies; you can see what your town accepts. There may be a disposal fee.
Appears in: What Do I Do With...?