If your bottle has been sealed and not left exposed to air there is a good chance it is still usable for your purposes.
Jake, can you tell me where you heard that NaNo2 goes zero when it attracts water ?
There doesn't seem to be a logical reason why it should.
Sources say that it shouldn't be used as a solution (dissolved in water), because instability in that aggregate state. So, dry it before use.
It's in sausage, actually even in fresh ones because it turns the stuff red (!) - sausages would look brown-grey without it...
It's in all the preserved meat stuffs you buy except cut fresh meat, and in almost ALL sausage, even fresh, because red.
And there's lots of water in the stuff, too. Doesn't seem to matter.
It sounds like H2SO4 in car batteries. the water dries off, you refill with water (not acid), because the crystals are still there and will dilute again...
They don't even say "store under low humidity and at a cool place."
Nothing at all.
If you have a source, please point me to it, TY - have to clear this up ;)