Boveda® packs can last between 6 and 10 months before needing replacement. It's lifespan may be increased by minimizing exposure to air. Once the humidity pack begins turning hard, the RH will begin to fall and this will signal the need for replacement.
CHOOSE 58% OR 62% RH—a personal preference depending on how you prefer your experience or on what the humidity level is where you are. Some prefer 58% RH for personal-use products or 62% for larger storage