[Amazin]

I bought a new membrane yesterday, a low pressure 4021 membrane. I was told that if I don't use it it will go out of date after a month? I also got another membrane, haven't use it yet but it's opened. (Does that mean I can't use it anymore after one month?

What is the best way to store them?

[mac74]

I very much doubt it, if its boxed and sealed and stored in a dry place, how could this happen? Who told you that?

[Arnold Palmer]

I keep spares on the shelf for six months or more.

Never had an issue.