Help How to keep Sodium nitrite??

[Nobodysfault]

Hello,
I got a small bag, 100mg of SN.
i got it from an unkown seller on ebay.
I have no way of knowing if its real SN or not, how much time does the supplier had it or if the bag was opened.
Please help me with the following questions:
A) if the SN is placed in a sealed bag, how long will it shelf life be?
B) i came across a post that said the SN turns into regular salt when in touch with air, which makes it usless. Is it ture? How long can it be out of the bag and still vaild to use? Please explain to me about how to treat and manage the SN (Add more tips, instructions and knowledge if you have some)
C) since the ebay seller is unknown, i guess its important to check if i was fooled or not, can someone send me the link to check the SN?
( and again it brings me to question B which is how long will i be able to use the sn from the second the bag was opened? Is it ture it turn into regular salt?)

Im trying to understand how to deal with SN in the right way so please answer to all of my question, Thank you!

 

[jake3d]

A) Almost indefinite. It's a salt, nothing much can happen to it. Keep the package sealed, away from light and humidity. Temperature is not a concern unless you leave it in the oven.
B) It turns into sodium nitrate not table salt. Only if left exposed to air for an extended amount of time (think days).
C) See here: https://sanctioned-suicide.net/thre...-an-aquarium-testing-kit-rough-version.18188/