How long does re-packaged SN last? (not in bottle)

[crystalskies31]

Hi,

I have some SN coming soon which is in a sealed bag (not bottle).
I heard that SN lasts almost 'infinitely' (in the PPH).
But if it has already been moved into a bag, doesn't that mean that it will expire faster?
If so, does anyone know how long?

Thanks
Edit: mostly asking just in case it gets even harder to source.

 

[NobodyKnowsMe]

If the bag is sealed, it will be fine. I think it is pretty common for SN to come in a bag. With a bag, you can get rid of the air before sealing it -- air/oxygen is bad for SN.