Hazard groups for work with biological agents

Hazard group 1

Biological agent that is unlikely to cause human disease, e.g. Escherichia coli, Saccharomyces cerevisiae (baker's yeast).

Hazard group 2

Biological agent that can cause human disease and may be a hazard. For most such agents there is effective treatment or prophylaxis available, such as vaccination. Most often, the risk of contagion is limited. Examples of such biological agents are Salmonella spp. (most strains), streptococcus, staphylococcus and adenovirus. At least hazard group 2 is applied in laboratories where materials that contain or may contain infectious agents are handled, but where the work does not involve working with infectious agents.

Hazard group 3

Biological agent that can cause severe disease in humans and animals and may be a serious hazard to work with. Often there is effective treatment or prophylaxis available, such as vaccination. It may spread to the community. Examples of such biological agents are Bacillus anthracis (anthrax), E. coli O157:H7 (ulcerative colitis, sometimes with serious side effects), Yersinia pestis (bubonic plague), yellow fever virus, HIV virus, rabies virus and SARS-CoV-2 (COVID-19).

Hazard group 4

Biological agent that can cause very severe human disease and is a serious hazard. There is usually no effective treatment or prophylaxis available, such as vaccination. It can have major consequences if the agent spreads to the community. Examples of such agents are Lassa fever virus, Ebola virus and Marburg virus.