Definition of "locked up" on MSDS: I am in the process of rearranging our chemical storage area.

Definition of "locked up" on MSDS: I am in the process of rearranging our chemical storage area.
Science drug lab equipment: Apparently school laboratories need a list, by item and quantity, of anything that could be targeted by a 'drug lab' break in.
Laboratory doors: I was wondering if it is a requirement that science room doors be locked when not attended by staff? If so, is this written down anywhere?