Oxoid - Technical Support

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FAQs

Answers to our more common technical enquiries.

Technical Support - FAQs

CLASSIFICATION OF MICRO-ORGANISMS ON THE BASIS OF HAZARD

It is obvious that not all micro-organisms have the same capacity to cause infections, and that infections vary in their incidence, their severity, and the availability of prophylaxis and therapy. By international agreement micro-organisms are now classified into groups or classes according to the hazard they offer to workers and the community. There are four groups, ranging from the relatively harmless to the very hazardous. The wording varies slightly from state to state and that used in Europe is shown in Table.

Lists of bacteria, viruses, fungi and parasites in Groups 2, 3 and 4 have been published by various national and international agencies, e.g. the European Union. Micro-organisms not listed in these Groups are assumed to be in Group 1, although some of them may be responsible for allergies. There are inevitable disagreements, globally, because of differences in the geographical distribution, incidence, and local significance.

Classification of micro-organisms on the basis of hazard and laboratory containment level

Class	Description	Laboratory
1	Unlikely to cause human disease	Level 1
2	May cause human disease; might be hazard to laboratory workers; unlikely to spread in community; laboratory exposure rarely causes infections; effective prophylaxis and therpy available.	Level 2
3	May cause serious human disease; may be serious hazard to laboratory workers; may spread in community; effective prophylaxis and therpy available.	Level 3
4	Causes serious human disease; serious threat to laboratory workers; high risk of spread in community; no effective prophylaxis and therpy available.	Level 4