shelf life of SN if Opened.

[Judy Garland]

Ok everyone. I was an idiot and wanted to check the seal on my Nitrite. Well guess what, I didn't think opening the child-proof cap WAS the seal. I thought it had foil over it. So I broke the seal and now my bottle has been opened. There were two small clumps in with the rest of the nitrite so it looks like at the factory (it was an American Source), somehow some moisture got into it. It doesn't look major though. So what is the shelf life of this? Is it still good for a few years? Mind you, I won't be here that long....but what do you all think? And yes, I yelled F*&^! When I realized I had broken the seal.