Methane ‘cooks’ are using empty propane tanks from the propane gas cylinder exchanges available at Wal-Mart, Kroger, and other chains. These contaminated cylinders have been found in many states at cylinder exchange and refilling locations as well as in hotel rooms and mobile laboratories, where the manufacturing of this illegal substance takes place.

Anhydrous ammonia is very corrosive and weakens the structure of the tank. It can be very dangerous when mixed with propane and hooked up to our backyard grills. As observed in the illustrations, a blue-green stain on any brass portion of a service valve is evidence that it may have been in contact with anhydrous ammonia. The pungent odor of ammonia on or near the cylinder is also an indication. If you suspect that a propane cylinder contains or has contained anhydrous ammonia, exercise extreme caution and restrict access to the area.

If you have any of these tanks contact your Fire Department, Hazardous Materials Emergency Response Unit or the nearest office of the United States Department of Justice’s Drug Enforcement Administration (DEA) for information on properly disposing of the cylinder. The National Propane Gas Association has posted more information here.