I own a complete collection of mint sets in OGP which I keep that way. I also bought all those sets again to break them out and place in separate albums (cents, nickels, dimes, etc) for viewing.
But when you crack out the coins, the case usually breaks and will not be even close to air tight if you choose to put them back in the case.
When I cracked out mine, I threw the cases in the garbage along with the little pieces that fell off of them.