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Biological Safety

Biological Safety

There is often confusion about the numbering of hazard groups and containment levels so here is a reference:

Hazard Groups and Containment Levels Explained:

All micro-organisms are assigned to a hazard group (see below for definitions)

HG       1   2   3   4

Work must be carried at the corresponding containment level

CL        1   2   3   4

Work with genetically modified organisms (GMOs) will fall into one of 4 classes.

CLASS  1   2   3   4

Not to be confused with the classification of safety cabinets


Class I – protects the user only (e.g. fume hood)
Class II – protects product and user (e.g. Tissue Culture Hood)
Class III –gives highest level of protection (e.g. glove box)

Do not confuse Microbiological Safety Cabinets with Laminar Flow Cabinets that have a flow of air towards the user. Laminar flow only protects the product and not the user.

Hazard Groups – definitions:

  1. Unlikely to cause human disease.
  2. Can cause human disease and may be a hazard to employees/students. Unlikely to spread into the community and there is effective treatment
  3. Can cause human disease and likely to be a serious hazard to employees/students. May spread to community but treatment available.
  4. Causes serious human disease and is a serious hazard to employees. Likely to spread to community. No effective treatment.

All work with biological substances should have a suitable and sufficient risk assessment performed before work takes place. Waste generated should be inactivated where possible before being disposed of via the clinical waste route for incineration.

Work involving the use of genetically modified organisms (GMO) or tissue, cells and products from these must be risk assessed using the standard form for GMO. Form GMB should be completed if the work involves the use of genetically modified animals e.g. knock in/out mice etc. This must then be assessed and approved by the Biological Safety Committee before any work takes place or animals are bred/purchased. If in doubt as to whether your work constitutes GMO/GMA seek advice from the Biological Safety Officer (BSO), Dr Walid Khaled, or the Department Safety Officer (DSO), Barney Leeke, before commencing work.

The use and storage of human tissue, including blood, is strictly regulated and you must seek advice from the BSO and/or DSO before planning any work using human derived biological material.

Experiments involving biological and radiological hazards must involve both the BSO and radiation protection supervisors (RPS), Prof. Mike Edwardson at the earliest stage.