Biological risk classification
Originally, analysis of diseases acquired in the laboratory showed that certain pathogens were responsible for infectious diseases that were more severe than others. These observations led to a classification system for pathogenic micro-organisms.
From 1969, the Public Health Service in the United States worked on the definition of four risk groups for pathogenic micro-organisms for humans. The work lasted for five years and the classification criteria were adopted in 1974 (CDC (Centers for Disease Control). 1974. Classification of Etiologic Agents on the Basis of Hazard, 4th Ed. U.S. Department of Health, Education and Welfare, Public Health Service, Center for Disease Control, Office of Biosafety, Atlanta, GA).
In 1979 the World Health Organisation (WHO) set up a working group on good microbiological practices. The work of this group led to the publication of a manual suggesting measures aimed at the protection of workers, the population, animal breeding and the environment (World Health Organisation. Biological Safety Manual, 1st edition, Geneva, Switzerland: WHO, 1984). As in the United States, the WHO adopted a classification system for pathogenic micro-organisms consisting of four risk groups. The work of the WHO would afterwards serve as a basis for a large number of national reference documents.
In the UK four "Hazard Groups" were also adopted in 1984 (ACDP : Advisory Committee on Dangerous Pathogens. 1984. Categorization of biological agents on the basis of hazard and categories of containment. Health and Safety Executive), after a tentative trial of three categories (A, B and C) between 1975 and 1978 which was not finally implemented.
In Europe, Directive 90/679/EEC on the protection of workers against biological risk was adopted in 1990. It contains a non-exhaustive list pathogenic micro-organisms for humans, also distributed into four risk groups.
Belgium drew on all of this work in order to adopt in 1993 three lists assigning risk categories to several hundreds of micro-organisms pathogenic to humans, animals and plants (bacteria, fungi, parasites, viruses, including prion proteins linked to transmissible spongiform encephalopathies). These lists have been regularly updated since that time and can be consulted from this website.
The setting up of risk groups of pathogenic organisms led, at the same time, to the implementation of good practices and containment measures aimed at ensuring individual and collective safety. As was done for organisms, four levels of containment were also defined to which increasingly strict safety measures were associated. These four levels were adopted on an international level, though not necessarily with unanimous classification and containment criteria.
The different constitutive elements of what would be later known by the term "biosafety" were in place: risk classification of organisms on the one side and containment levels on the other. Between them, a key element would develop over time: the assessment of biological risks.