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Biological safety

Provision of guidance to control the significant risks to human health from biological agents people may be exposed to at work.



This guidance applies to all microbiological laboratories at the University of Bath. It covers not only deliberate work with biological agents such as in research projects but also incidental exposure such as in the taking of blood or handling of anatomical specimens. However, it does not cover exposure as a result of other routine work such as catching flu from a colleague.

Biological agents are considered to be 'substances hazardous to health' in terms of Health and Safety Legislation and so are governed by the Control of Substances Hazardous to Health (COSHH) Regulations 2002. This requires employers to prevent or reduce employees’ exposure to hazardous substances.

This guidance provides a basic overview of key aspects for safely managing exposure to biological agents in laboratories.

The SHEW biological safety guidance document provides more detailed information and should be read by all users.

Classification and assessment

Biological agents are classified into four ‘hazard groups’ according to the following infection criteria:

  • their ability to cause infection

  • the severity of the disease that may result

  • the risk that infection will spread to the community

  • the availability of vaccines and effective treatment

Hazard Group 1 is the least harmful, while Hazard Group 4 is the most severe. The University of Bath only works with Hazard Group 1 and 2 biological agents and so laboratories are assigned at a maximum of containment level (CL) 2.

COSHH (Schedule 3) requires every employer to ensure that measures taken to adequately control the exposure of employees to biological agents include − in particular − the most suitable combination of containment measures, taking into account:

  1. The nature of the activity.

  2. The minimum containment level.

  3. The risk assessment, and

  4. The nature of the biological agent concerned.

Laboratory practice

The following need to be taken into consideration in order to adequately control exposure to biological agents in laboratories:

  • access to a CL2 laboratory must be limited to authorised persons only

  • safe working practices and procedures including basic Good Microbiological Principles (GMP) must be established and communicated

  • use of a microbiological safety cabinet where there is risk of exposure due to aerosol generation

  • correct use of lab equipment to minimise contamination particularly when aerosols could be generated

  • identification and provision of Personal Protective Equipment (PPE)

  • procedures for dealing with incidents such as spillages and puncture wounds/cuts

  • sterilisation and disinfection procedures ensuring correct protocol is followed dependent on the biological agent


If you have any questions, please contact us.

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