Prauge #1 shelf life?

[georgeamer]

Is there a "shelf life" for Prauge #1?
I have some that is about 4 years old.....will it still have "punch"?
george

[Habanero Smoker]

I have used curing salts that were 2.5 years old. If stored properly the self life is almost indefinite. Sometime there are signs that show it is no good. If it has hard lumps, throw it out. If it has lumps, but they can be broken apart easily with light pressure, it still can be good. There are times there are no signs. It it has been exposed to high temperatures for a long period of time, it could alter and break down the nitrites. I would test it on a few thin cuts of meat, such as pork chops to tests it curing abilities.