Research

Biosafety Levels for Management of Biological Organisms

Summary of recommended biosafety levels for management of biological organisms. The laboratory director is specifically and primarily responsible for assessing the risks and applying the appropriate biosafety levels. The Institutional Biosafety Committee (IBC) can be of great assistance in performing and reviewing the required risk assessment.

Source: Biosafety in Microbiological and Biomedical Laboratories (BMBL).
Biosafety Levels for Management of Biological Organisms
Biosafety Level (BSL) Controls Corresponding Risk Group/Representative Organisms
BSL-1
  • Work is conducted on open benchtops using standard microbiological practices.
  • Benchtops are resistant to water, heat, solvents, and other chemicals.
  • Laboratory furniture must be nonporous for easy cleaning and decontamination.
  • A sink is available for hand washing.
  • Researchers must have lab-specific training.
  • Laboratory coats, gloves, and face and eye protection as needed.
Risk Group 1 agents are not associated with disease in healthy adults. Examples  include: E. coli K-12, Laccaria bicolor, Saccharomyces cerevisiae, Lactobacillus acidophilus, Baculoviruses, adeno-associated virus.
BSL-2
  • BSL-1 and
  • Work may be conducted on open benchtops.
  • Biosafety cabinets (BSCs) or other physical containment devices used for procedures causing splashes or aerosols.
  • An autoclave must be available for decontamination of waste.
  • Limited access to laboratory, warning signs, sharps precautions.
  • A biosafety manual is required with standard operating procedures for storage, use, waste disposal, emergency response, medical surveillance, etc.
  • Laboratory coat, gloves, and face and eye protection as needed.
Risk Group 2 agents are associated with human or animal diseases that are rarely serious. Effective treatment and preventative measures are available. Examples include: working with human blood, Streptococcus pyogenes, Giardia spp., Microsporum canis, human adenoviruses, Hepatitis virus.
BSL-3
  • BSL-2 and
  • Biosafety cabinets or other physical containment devices used for all manipulations of agents.
  • Controlled access to laboratory, self-closing double doors, negative pressure in laboratory, exhaust air not recirculated.
  • Protective clothing; gloves; and face, eye, and respiratory protection as needed.
Risk Group 3 agents are associated with serious or lethal human or animal diseases. Effective treatment and preventive measures may be available. Examples include: Yersinia pestis, Francisella tularensis, Coccidioides immitis, Prions, Hantavirus, and Influenza viruses A H1N1 (1918), H2N2 (57-68), and H5N1 (bird flu).
BSL-4
  • BSL-3 and
  • Separate building or zone, dedicated supply and exhaust air, and dedicated vacuum systems and decontamination systems.
  • All procedures conducted in Class III BSCs or Class I or II BSCs with full-body, air-supplied, positive-pressure suit.
  • Change clothing before entering; shower on exit.
Risk Group 4 agents cause serious or lethal human or animal disease and are readily transmitted. Effective treatment and preventive measures are not usually available. Examples include: Smallpox virus, Ebola virus. No bacteria, fungi, or parasites in this group.