Two main standards published by IPC (Association Connecting Electronics Industries) and JEDEC (Joint Electron Device Engineering Council) about dry storage is available:
Download J-STD-033B.1.pdf (IPC/JEDEC J-STD-033B.1 (Jan 2007) - Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Devices)
Download J-STD-020C.pdf (IPC/JEDEC J-STD-020C (July 2004) - Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface MountDevices)
According to J-STD-033B, SMD packages not sealed in a MBB (Moisture Barrier Bag) may be placed in a dry atmosphere cabinet, maintained at not greater than 5% RH. Storage in these dry cabinets may be considered equivalent to storage in a MBB with unlimited shelf life.
In addition, storage of SMD packages not sealed in a MBB, in cabinets maintained at not greater than 10% RH should be limited to a maximum time. If the time limit is exceeded they should be baked to restore the floor life.
This means, storing MSDs in a drying cabinet maintained at not greater than 5% RH, offers unlimited shelf life without using MBB and removes possible re-baking costs which are much more than the storage costs.
