Saturday, 7 October 2017

Understanding Biosafety Levels


The handling of any biological agent requires an understanding of the agent and the risk of exposure to personnel, the facility, and the environment. The U.S. CDC and the NIH have used risk assessment to develop four ascending biosafety levels of containment required for use with biological agents, as follows:

  • BSL 1 – work or processing involving well-characterized agents not known to cause disease in healthy adult humans, and of minimal potential hazard to personnel and the environment
  • BSL 2 – working with or processing agents of moderate potential hazard to personnel and the environment
  • BSL 3 -- processing or handling of indigenous or exotic agents that may cause serious or potential lethal disease as a result of exposure by the inhalation route
  • BSL 4 –working with or processing a dangerous and exotic agent that poses a high individual risk of aerosol-transmitted laboratory infection and life-threatening disease.


In April 2002, the NIH published guidelines specifically directed at the industry that took a similar approach, but with more detail, called NIH Guidelines on Recombinant DNA:

  • Risk Group 1 (RG1) – the agents used are not associated with disease in healthy adult humans
  • Risk Group 2 (RG2) – the agents are associated with human disease that is rarely serious and for which preventive or therapeutic interventions are often available
  • Risk Group 3 (RG3) – the agents are associated with serious or lethal human disease for which preventive or therapeutic interventions may be available
  • Risk Group 4 (RG4) – the agents are likely to cause serious or lethal human disease for which preventive or therapeutic interventions are not usually available


This is an extract from an interesting article by Herman F. Bozenhardt and Erich H. Bozenhardt. The full text is available on Pharmaceutical Online.

Posted by Dr. Tim Sandle