10 CFR § 95.29 - Establishment of Restricted or Closed areas.
(a) If, because of its nature, sensitivity or importance, classified matter cannot otherwise be effectively controlled in accordance with the provisions of §§ 95.25 and 95.27, a Restricted or Closed area must be established to protect this matter.
(b) The following measures apply to Restricted Areas:
(1) Restricted areas must be separated from adjacent areas by a physical barrier designed to prevent unauthorized access (physical, audio, and visual) into these areas.
(2) Controls must be established to prevent unauthorized access to and removal of classified matter.
(3) Access to classified matter must be limited to persons who possess appropriate access authorization or other written CSA disclosure authorization and who require access in the performance of their official duties or regulatory obligations.
(5) Each individual authorized to enter a Restricted or Closed Area must be issued a distinctive form of identification (e.g., badge) when the number of employees assigned to the area exceeds thirty per shift.
(6) During nonworking hours, admittance must be controlled by protective personnel. Protective personnel shall conduct patrols during nonworking hours at least every 8 hours and more frequently if necessary to maintain a commensurate level of protection. Entrances must be continuously monitored by protective personnel or by an approved alarm system.
(c) Due to the size and nature of the classified material, or operational necessity, it may be necessary to construct Closed Areas for storage because GSA-approved containers or vaults are unsuitable or impractical. Closed Areas must be approved by the CSA. The following measures apply to Closed Areas:
(1) Access to Closed Areas must be controlled to preclude unauthorized access. This may be accomplished through the use of a cleared employee or by a CSA approved access control device or system.
(2) Access must be limited to authorized persons who have an appropriate security clearance and a need-to-know for the classified matter within the area. Persons without the appropriate level of clearance and/or need-to-know must be escorted at all times by an authorized person where inadvertent or unauthorized exposure to classified information cannot otherwise be effectively prevented.
(3) The Closed Area must be accorded supplemental protection during non-working hours. During these hours, admittance to the area must be controlled by locked entrances and exits secured by either an approved built-in combination lock or an approved combination or key-operated padlock. However, doors secured from the inside with a panic bolt (for example, actuated by a panic bar), a dead bolt, a rigid wood or metal bar, or other means approved by the CSA, do not require additional locking devices.