Biosafety Level 3 Containment

Level 3 activity involves organisms or systems which pose a significant risk or represent a potentially serious threat to health and safety of workers, therefore,  facility design plays a significant role in safety.  Such facilities include special engineering design features and containment equipment. 

These facilities are usually separated from the general traffic flow by controlled access corridors, air locks, locker rooms, or other doubledoor entries.  Biosafety cabinets are required for all technical manipulations that involve viable cultures (no work is allowed on an open bench). 

The surfaces of all walls, floors and ceilings are sealed and, therefore, impervious to liquids that may spill onto them.  This means that all penetrations (telephone, lights, plumbed lines for gas, vacuum, electrical lines, electrical switches, etc.) are caulked, collared or sealed to prevent leaks. 

The collars and seals are also made of material which can be cleaned.

The ventilation system in the Biosafety Level 3 facility is designed to exhaust more air than is supplied, resulting in a directional airflow from the outer corridors, which are regarded as clean into the laboratory, which is regarded as contaminated.  The air is usually discharged to the outdoors and not recirculated to other parts of the building without appropriate filtration treatment.

This laboratory is suitable for experiments involving agents that are associated with serious and potentially life-threatening disease for which preventative or therapeutic interventions may be available.

Activities include:

The production of large volumes or high concentrations of certain Risk Group 2 and all Risk Group  microorganisms or viralinfected cells (where the virus is infectious for man and requires level 3 containment).

1. Microorganisms of moderate biohazards potential such as those in Risk Group 3 or Biosafety Level 3.
2. Cell tissue culture experiments that involve large volumes or high concentrations of virus-infected cells (where the virus is infectious for man or require level 3 containment).
3. Recombinant DNA research requiring physical containment at the BL3 Level.
4. Oncogenic viruses that have human cells in their host range.

Biosafety Level 3 organisms differ from those at Level 2 because there is a real potential for infection due to aerosol exposure.  Organisms such as Mycobacterium tuberculosis, prions, Human Retroviruses, St. Louis encephalitis virus, and Coxiella burnetii belong in this category.