Seal

The caster places this spell on a chest or other container. The chest is then absolutely sealed against the detrimental effects of normal environmental forces. A sealed chest would protect the contents from moisture (even immersion), gas, heat (up until the point where the chest caught on fire), etc. In an extremely hostile environment (such as a fire), the sealed chest must make a saving throw each round to retain integrity and protect its contents. Mages often use this spell to protect spellbooks, spell components, and other valuable items.

The material component (not consumed) is a chest worth at least 25 gp.