How to dispose of propane tanks

The Department of Transportation (DOT) strictly regulates the manufacture and transport of pressurized cylinders, requiring periodic requalification testing (usually every 12 years for 20lb tanks). The EPA regulates large-scale venting of propane under the Clean Air Act, though it is not an ozone-depleting substance. Household propane tanks are universally banned from municipal trash and curbside recycling bins due to their severe explosive hazard when crushed.

For standard 20lb BBQ tanks, the easiest disposal method is utilizing a national tank exchange program like Blue Rhino or AmeriGas. You can leave an old, out-of-date tank beside the exchange cage at retailers like Walmart, The Home Depot, or convenience stores. The companies will retrieve it for refurbishment or safe recycling. For the small 1lb green camping cylinders, disposal is much harder; they must typically go to a municipal Household Hazardous Waste facility, though some national parks run localized collection programs.