Whether you have important documents (birth certificates, social security cards, etc.) stored in files in a desk, cabinet, box, or envelopes, you can add a few packets of silica gel to keep them protected.
5. To use in each container in your basement, garage, or storage unit to absorb excess moisture.
These get pulled out of boxes only once a year, so using silica gel packets in your Christmas boxes is a smart idea.
References from: Make Life Lovely