Share this“Bio-safety Level 3 (BSL3) is appropriate for agents with a known potential for aerosol transmission, for agents that cause serious and potentially lethal infections and that are indigenous or exotic in origin.” 1
“All procedures involving the manipulation of infectious materials must be conducted within a BSC (preferably Class II or Class III), or other physical containment device.”1
Any consideration of primary engineering controls in a Level 3 animal facility needs to maximize the safety of the researchers and the protection of the animals as a priority. The above two statements, as taken from the newly released BMBL 5th Edition, may serve here as a framework for this discussion on the use of primary engineering controls in such a facility.
The use of Class II Biological Safety Cabinets (BSCs) is extensive throughout all areas of animal research. Many different types of Class II cabinets and even some Class III cabinets may be used based upon the safety and application required: animal handling, cage changing or dumping, procedures, surgeries, necropsy, etc. Selection of the proper Class and Type of BSC needs to be made by a certified bio-safety professional. Adaptations to the design of the BSC may also be necessary to facilitate the specific research being conducted within the physical limitations of the facility.
Animal Handling/Cage Changing of Rodents: Mobile and Fixed Class II Type A2 BSCs
Used in animal holding rooms for the safe handling of mice and rats, a Type A2 BSC is a 70% recirculation/30% exhaust cabinet. This type of BSC offers the researcher proper bio-hazard protection through a containment air barrier of 100 FPM (feet per minute) minimum across the front access of the cabinet. The animal is likewise protected by uni-directional HEPA filtered air in the work zone and through the containment air barrier.