Better yet, consider a computerized card key system. A lost card can be quickly written out of the system and the computer can track personnel movements. If it was tied in to the security system one pass of the card would turn off the alarm, open the door, tell you who did it, and when. If there are any floor drains, make sure that trap primers are installed. These are devices that keep water in the trap part of the drain line to keep odors from coming back into the room.
Ventilation is extremely important, especially in narcotic storage areas.
A separate exhaust fan that runs continuously is the most effective way of handling this. Make sure there is a source of make-up air such as a vent in the door to that room. Before answering that question, you must make sure that your inventory contains only those items that are really needed. The inventory in a properly run property section should show only a moderate growth that is predictable. Now let's look at storage.