From the number of posts over the past couple of weeks on the various fora about meth makers using propane tanks to store anhydrous ammonia, you’d think that there was an epidemic of contaminated propane tanks out there that innocent glassmakers are going to get. Case in point (from LE):
I wanted to let you all know about something that I was not aware of.
Meth cooks are getting the propane tanks from the exchanges at Wal-Mart, Kroger, etc. and emptying them of the propane. Then, they are filling them with anhydrous ammonia (which they now have a recipe for by the way). After they are finished with them, they return them to the store. They are then refilled with propane and sent back for you and me to buy.
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 grills, etc.
According to our presenter, you should inspect the propane tank for any blue or greenish residue around the valve areas. If it is present, refuse to purchase that one.
I researched the information, and you should check out the following website for more details. They also have pictures you can show.
Be careful out there!
The link takes you to a Safety Alert put out by the National Propane Gas Association to its members. These are the guys who refill propane tanks, advising them of a situation, and what to look for. It is very obvious when a propane tank has been used for anhydrous ammonia — the brass valve assembly turns green from the ammonia attacking the brass.
But this is nothing for us to worry about — refillers must follow NFPA 58 (the Propane Gas national code) — and the code clearly states that any business that refills propane tanks MUST, repeat MUST inspect all tanks prior to refilling. Inspection is not limited to a mere visual inspection – they must also check that the tank is not due for pressure testing, is not corroded, etc. The Safety Alert does nothing more than advise refillers to be on the lookout for tanks that have been contaminated with anhydrous ammonia and how to deal with them.
It is very unlikely that any contaminated tank will ever reach the consumer level — and then only because the refiller did not follow NFPA 58 — which in and of itself is grounds for the refiller to lose their license to refill propane tanks.
Certainly keep your eyes open and watch for any contaminated tanks, but don’t lose any sleep over this.