Shells could live for more then 100 years
you can [put it in a case and lock it in a safe.
No. because they proably still addictive.. No. because they proably still addictive..
It is not safe. Bacteria could build up.
Depends what they are coloured with. Were you intending to eat the shells?
Is it safe to take azithromycin if it expired 2 years ago
When the shells are closed. If open, tap on the shell. If it closes then it is safe to eat. Do not eat opened ones that remain open.
never buy painted shells. they are all toxic because they dissolve in saltwater. If you want, you can buy polished shells that don't have any type of gloss or paint coat. polished shells are perfectly safe an equally pretty!