12. Facility Design (Secondary Barriers)

The design of the facility is important in providing a barrier to protect persons working inside and outside the laboratory within the facility, and to protect persons or animals in the community from infectious agents which may be accidentally released from the laboratory.

The laboratory management is responsible for providing facilities commensurate with the laboratory's function and the recommended biosafety level for the agents being used.

The recommended secondary barrier(s) will depend on the risk of transmission of specific agents. For example, the exposure risk for most laboratory work in Biosafety Levels 1 and 2 facilities will be direct contact with the agents, or inadvertent contact exposures through contaminated work environments. Secondary barriers in these laboratories may include the separation of the laboratory work area from public access, availability of a decontamination facility (e.g., autoclave), and hand-washing facilities.

As the risk for aerosol transmission increases, higher levels of primary containment and multiple secondary barriers may be necessary to prevent infectious agents from escaping into the environment. Such design features could include specialized ventilation systems to assure directional air flow, air treatment systems to decontaminate or remove agents from exhaust air, controlled access zones, airlocks at laboratory entrances, or separate buildings or modules for isolating the laboratory.