Biohazards Risk Assessment

To identify and manage/contain risks in the workplace associated with the biohazardous agent itself and how and where the agent will be used, in order to protect the health of workers, the public, and natural or managed environments. Risk management includes a combination of the following controls:

  • Safe work practices
  • Safety equipment
  • Administrative policies
  • Proper facilities

The PI/laboratory director is responsible for identifying the hazards associated with the agent and/or procedures, applying the appropriate risk management controls, and advising the staff of both the risks and controls.  The following questions should be considered:

  • What are the hazardous materials in the laboratory?
  • What procedures are hazardous or increase the hazardous nature of the materials?
  • What might happen if there was a problem?
  • Who/What may be exposed and how?
  • How serious are the consequences?
  • How likely is it to happen?
  • How can this be minimized?

Pre-existing diseases, medications, compromised immunity, pregnancy, or breast-feeding are some of the conditions that may increase the risk of an individual acquiring a laboratory acquired infection.  Consultation with an occupational physician knowledgeable in infectious diseases is advisable in these circumstances.  The primary factors to consider in risk assessment and selection of precautions fall into the following two categories:

Laboratory-specific hazards

  • Amount of biohazardous material to be used or stored.
  • Concentration of the material.
  • Use of equipment or procedures that impart energy to the material resulting in dissemination, aerosolization, splash, or splatter.
  • Use of equipment or procedures that can cut, scratch, or puncture skin.
  • Proximity of susceptible hosts or environment.
  • Animal experiments.

Agent-specific hazards

  • Capability to infect/cause disease in a susceptible human, animal, or plant host.
  • Virulence as measured by disease severity.
  • The availability of preventive measures and effective treatments for the disease.
  • Probable routes of transmission of infection (respiratory, mucous membrane transmission higher risk than parenteral or ingestion routes).
  • Infective dose or concentration needed to cause disease.
  • Stability in the environment, resistance to disinfectants.
  • Host range, species affected (e.g. ecotropic, amphotropic, zoonotic).
  • Origin or endemic vs. exotic nature: Non-indigenous agents are of special concern because of their potential to introduce risk of transmission, or spread of human, animal, or plant diseases from foreign countries into the United States.  The Centers for Disease Control and Prevention and US Department of Agriculture regulate the import of disease agents, clinical or environmental specimens, and other potentially infectious materials.  Some agents are also regulated for interstate movement and for export.

Tools for Risk Assessment

Both the National Institutes of Health (NIH) and the World Health Organization (WHO) describe four general risk groups (RG) that address the risk to both the laboratory worker and the community/environment and are based on (see ):

  • An agent’s capability to infect and/or cause disease in a susceptible human host.
  • An agent’s virulence as measured by the severity of disease.
  • Availability of preventive measures and effective treatments for the disease.
  • Route of transmission of the natural disease.


Note that:

  • The classification is intended for human pathogens but can also be applied to plant or animal pathogens.
  • Risk groups correlate with, but do not equate to, biosafety levels; biosafety levels also take into account lab operations and procedures used.


Important guidance documents for risk assessment include Section VIII, CDC Biosafety in Microbiological and Biomedical Laboratories (BMBL) 5th Edition, 2009 and Appendix B of the NIH Guidelines.