Select storage furniture with protective qualities. Choose inert powder-coated steel or plastic storage racks and shelving over wood-based products that off-gas harmful acids. Oak, one of the most common furniture materials, is also one of the worst. Particle board or plywood decking are also not appropriate for archival storage. These processed woods and the adhesives used emit acids and formaldehydes that can be extremely damaging to your collections. If you have wood storage furniture and can't afford to replace it with powder-coated metal, here are some of the steps you can take to help:
Dust can also be acidic and hold moisture, so cover hanging items and enclose shelved items in containers before storing them.
For more information, including a list of woods and their pHs, see CCI's Technical Bulletin #21: Coatings for Display and Storage in Museums or the NEDCC Preservation Leaflet: 4.2 Storage Furniture.