Biological safety laboratories are designed and equipped to safely handle pathogens and other potentially hazardous materials. These facilities vary widely in the type and degree of risk of the materials being handled. Sometimes these labs are constructed and operated for a specific application that will define the required Biological Safety Level or BSL.
Biological Safety Levels range from 1 to 4, with BSL-4 offering the highest level of bio-containment.
Biosafety Level 1 Laboratory
This Biosafety Level describes labs that handle materials with a minimal risk. This affords only basic protection for the operator and environment. Biological Safety Level 1 facilities are used for applications involving well defined agents, not known to be hazardous or generally do not cause disease in immunocompetent adult healthy humans.
Biosafety Level 2 Laboratory
This level is for labs handling materials that may present a moderate risk to personnel and the environment. BSL-2 labs require that the laboratorians have a higher level of training specific to the safe handling of pathogens. Further, staff must be supervised by scientists that are trained to oversee all processes and procedures that involve infectious materials. These laboratories also have appropriate access restrictions while the lab is active.
Another key distinction of these operations relates to the use of primary containment systems. Certain procedures will be conducted within biological safety cabinets.
The Biosafety Level 2 laboratory is generally utilized for work that involves “the broad spectrum of indigenous moderate-risk agents that are present in the community and associated with human disease of varying severity.” (BMBL)
Biosafety Level 3 Laboratory
The Biosafety Level 3 laboratory is significantly more advanced than the BSL-2 lab in terms of its design, infrastructure and operational procedures and practices. These labs incorporate a variety of primary containment equipment, which may include Class III BSCs for handling materials with a high or unknown risk level. From a facility-engineering standpoint, another critical aspect are the secondary containment systems. These facilities utilize sophisticated HVAC systems and controls. The BSL-3 laboratory is generally utilized for work “with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection.” (BMBL).
Biosafety Level 4 Laboratory
The BSL-4 laboratory is a far more restrictive and less common type of facility. This lab is applicable for work with “dangerous and exotic agents that pose a high individual risk of life-threatening disease, which may be transmitted via the aerosol route and for which there is no available vaccine or therapy.” (BMBL)
The Level 4 laboratory can be set up so that all work is conducted within a Class III cabinet (also called a ‘cabinet laboratory). A ‘suit laboratory’ requires that personnel wear protective suits that operate under positive pressure.
This type of laboratory presents an additional layer of complex requirements in regard to containment, separation of facilities, biosecurity, engineering, infrastructure, HVAC controls, training, policies and procedures, etc.
Please visit our section on Biosafety Level 3 laboratories.
