Classification of Biological Agents

Biological Agents are classified in the Code of Practice to the Safety, Health and Welfare at Work (Biological Agents) Regulations 2013 and 2020, into four risk groups – groups 1, 2, 3 and 4.

The classification system is based on whether:

• The agent is pathogenic to humans
• The agent is a hazard to employees
• The agent is transmissible to the community
• There is effective treatment or prophylaxis available.

Risk Group Categorisation

Under the classification system, Group 1 agents are the least hazardous whilst Group 4 are the most hazardous.

Schedule 1 of the Code of Practice provides a non-exhaustive classification list of biological agents. Only agents in hazard groups 2 – 4 are listed. If the agent you are working with is not on the list, the categorisation will need to be determined by assessment based on the criteria above. Biological agents should not be automatically categorised into hazard group 1.

The categorisation system gives an indication of the inherent hazard of the biological agent but it does not take account of the work that may be carried out with the agent or the exposure of sensitive groups, for example, pregnant employees to the agents.

The following websites may be of assistance in helping classify and risk assess the biological agent.

• Government of Canada, Pathogen Safety Data Sheets
• Gestis Biological Agents Database

Note: The classification of the biological agent in the Code of Practice to the Safety, Health and Welfare at Work (Biological Agents) Regulations 2013 and 2020, takes precedence over any classification given in these websites.