A new widespread threat is growing in the United States: Propane tanks are becoming weak, which means they are becoming dangerous.

People are stealing or buying these tanks and using them to transport the anhydrous ammonia used to cook chemicals for methamphetamine.

Meth cooks are getting propane tanks from exchanges at Wal-Mart, Kroger, etc. and emptying them. Next, they fill them with anhydrous ammonia and return them empty to the store when finished. These empty tanks contain varying amounts of anhydrous ammonia residue. Unaware of prior use and potential hazard, stores refill tanks with propane and make them available for purchase.
 
In some instances, drug makers use barbeque-type propane tanks to steal anhydrous ammonia from businesses or farm operations that have large ammonia tanks on site.

Anhydrous ammonia is a deadly chemical commonly used on farms as a source of nitrogen fertilizer. If this corrosive chemical is mishandled or misused, it can cause severe chemical and potentially fatal burns to the eyes, skin, and lungs.

The danger of putting anhydrous ammonia in a propane tank is that it can corrode the tank valve. The deterioration leads to cracking of the valve body or its components and can ultimately result in a violent, unexpected explosion of the valve from the cylinder. Worse still, anhydrous ammonia is corrosive so if any of it happens to be in the tank it can cause severe burns to the skin and lungs.

The warning signs of a tank made defective by anhydrous ammonia are blue, green, or blue-green residue around the valve. It is recommended that if you spot signs of contamination when purchasing a cylinder, refuse it. If you discover that you have a tank with signs of contamination, don’t move it. Call your local fire department for proper handling and disposal.