Saving Throws
Effects that deal damage generally damage unattended objects normally but don’t damage held or attended objects unless the effect specifically says otherwise. Effects that do something other than deal damage affect only objects if their descriptions specifically say so (only common with spells) or note “(object)” in the description of the effect’s saving throw. An object’s total saving throw bonus for Fortitude, Reflex, and Will saves is equal to the object’s caster level or item level. An object that is held or worn uses the saving throw bonus of the creature carrying it if that bonus is better than its own saving throw bonus. Items with a caster level or item level of 0 don’t receive saving throws when unattended.
Source
Core Rulebook pg. 409