Some bacteria, viruses, fungi, and other biological agents can infect humans and make them ill. These are referred to as pathogens. Many other biological agents are, by contrast, harmless (apathogenic) or only harmful to vulnerable individuals (opportunistic pathogens). However, employees in many work settings, can be exposed to very high concentrations of biological agents that are associated with various health risks. The potential hazards represented by biological agents have to be documented by employers when workplaces are risk assessed.

What risk groups are there?

Biological agents are classified into four risk groups, depending on the risk of infection they pose to humans, so that employers can take appropriate practical protective measures. The classifications take account of the biological agents’ contagiousness, the severity of the illnesses they cause, and how easy those conditions are to treat. Biological agents in risk group 1 pose the lowest risk of infection, while those in risk group 4 pose the highest.

Risk group 1

Biological agents that are unlikely to cause human disease.

Risk group 2

Biological agents that can cause human disease and might be a hazard to employees; they are unlikely to spread to the community; there is usually effective prophylaxis or treatment available.

Risk group 3

Biological agents that can cause severe human disease and present a serious hazard to employees; they may present a risk of spreading to the community, but there is usually effective prophylaxis or treatment available.

Risk group 4

Biological agents that cause severe human disease and are a serious hazard to employees; they may present a high risk of spreading to the community; there is usually no effective prophylaxis or treatment available.

The classification of biological agents into risk groups is governed in German law by the Biological Agents Ordinance (Biostoffverordnung, BioStoffV), which implements the German Occupational Safety and Health Act (Arbeitsschutzgesetz, ArbSchG) in this field and transposes EU Directive 2000/54/EC. Biological agents are classified into risk groups at the national and EU levels.

How are biological agents classified?

In Germany, biological agents are classified by the Federal Ministry of Labour and Social Affairs (Bundesministerium für Arbeit und Soziales, BMAS). The ministry is advised about this issue by the Committee on Biological Agents (Ausschuss für Biologische Arbeitsstoffe, ABAS) - represented by its Subcommittee on the Scientific Evaluation and Classification of Biological Agents (Unterausschuss “Wissenschaftliche Bewertung und Einstufung von Biostoffen”) - and the German Social Accident Insurance Institution for the Raw Materials and Chemical Industry (Berufsgenossenschaft für Rohstoffe und chemische Industrie, BG RCI).

The biological agents that have been classified are documented in the following Technical Rules for Biological Agents (Technische Regeln für Biologische Arbeitsstoffe, TRBA) in accordance with their biological origins:

• TRBA 460 Classification of fungi into risk groups (Einstufung von Pilzen in Risikogruppen)
• TRBA 462 Classification of viruses into risk groups (Einstufung von Viren in Risikogruppen)
• TRBA 464 Classification of parasites into risk groups (Einstufung von Parasiten in Risikogruppen)
• TRBA 466 Classification of prokaryotes (bacteria and archaea) into risk groups (Einstufung von Prokaryonten (Bacteria und Archaea) in Risikogruppen)
• TRBA 468 List of cell lines and activities involving cell cultures (Liste der Zelllinien und Tätigkeiten mit Zellkulturen)

These Technical Rules are published in the Joint Ministerial Gazette (Gemeinsames Ministerialblatt, GMBl.). As an institution within the jurisdiction of the Federal Ministry of Labour and Social Affairs, the Federal Institute for Occupational Safety and Health (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, BAuA) makes the Technical Rules for Biological Agents directly available for download on its website.

Documentation of other critical attributes

Biological agents are classified at the species level. In rare instances, it is also possible for classifications to be assigned to variants of a species (e.g. strains with properties that diverge from those of typical representatives of the same species) or to groups of species (e.g. genera). In addition to its risk group, other health-critical properties of the biological agent (e.g. its potentially sensitising or toxic effects) are documented with specific notes in the Technical Rules for Biological Agents (TRBA). Further information is sometimes added as well, including the biological agent’s pathogenicity to plants or animals and its routes of transmission. TRBA 468 not only lists various biological agents, but also includes concrete rules for good cell culture techniques.

Inquiries about the classification of biological agents can be submitted to the Subcommittee on the Scientific Evaluation and Classification of Biological Agents via the ABAS Administration. Such inquiries are received, for example, when research institutes, companies, or other organisations plan activities involving biological agents that need to be assigned to a risk group. TRBA 450 stipulates the information required before this can be done.

Furthermore, the Subcommittee on the Scientific Evaluation and Classification of Biological Agents also conducts its own projects for the classification of biological agents together with the German Social Accident Insurance Institution for the Raw Materials and Chemical Industry, looking for example at previously unclassified influenza viruses during influenza outbreaks. In some cases, ABAS collaborates on the classification of biological agents with the Central Committee on Biological Safety (Zentrale Kommission für Biologische Sicherheit, ZKBS). This happens, for example, when a biological agent is subject to classification both by ABAS and, pursuant to the Genetic Engineering Safety Ordinance (Gentechniksicherheitsverordnung, GenTSV), by the ZKBS.

The research undertaken by BAuA into biological agents includes projects intended to support classification processes by studying laboratory-scale cell models.

Differences between national and EU-wide classification

The national classification system in Germany has greater reach than the EU’s classifications of biological agents.

Biological agents are classified into risk groups 2, 3, and 4 at the EU level, while risk group 1 is not referred to (2000/54/EC, Annex III). Thanks to the national classification work that is constantly ongoing, the lists of classified biological agents in the Technical Rules for Biological Agents are considerably more comprehensive than those in Annex III of Regulation 2000/54/EC.

The classification of biological agents into four risk groups is rooted in the concept of four biosafety levels, a global convention that, with some national and regional variations, is explained in the guidelines published by the World Health Organisation (WHO Laboratory Biosafety Manual, 4th ed., Geneva, 2020) and the United States Centers for Disease Control and Prevention (Biosafety in Microbiological and Biomedical Laboratories, 6th ed., CDC, 2020).

The classification into four risk groups enables the practical implementation of four defined protection levels with assigned technical, organizational and personal protection measures for activities with an assigned protection level.