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Working in the lab

Health and Safety in the lab

Health and safety in the laboratory is important, particularly when working with pathogenic bacteria. Safety measures in the laboratory are put in place to protect yourself, other workers, the environment and the wider community.

Control of Substances Hazardous to Human Health (COSHH) Regulations 2002 define 4 levels of containment for laboratory work, with each level being appropriate for work with organisms from the equivalent Hazard Group (HG) https://www.hse.gov.uk/pubns/priced/l5.pdf

Although the COSHH guidelines are UK specific, there will be similar guidelines for each country.

Classification of microorganisms into hazard groups

Hazard Group Definition Examples
Group 1 Unlikely to cause human disease Lactobacillus, Saccharomyces cerevisiae
Group 2 Can cause human disease and may be hazardous to employees; it is unlikely to spread to the community and there is usually effective prophylaxis or treatment available Staphylococcus aureus, Klebsiella pneumoniae
Group 3 Can cause severe human disease and may be a serious hazardous to employees; it may spread to the community, but there is usually effective prophylaxis or treatment available Mycobacterium tuberculosis, Salmonella typhi
Group 4 Causes severe human disease and is a serious hazardous to employees; it is likely to spread to the community and there is usually no effective prophylaxis or treatment available Lassa fever virus, Nipah virus (no known Group 4 bacteria listed in the UK)

The Approved List of Biological Agents, published by the Health and Safety Executive (HSE) lists the hazard groups of microorganisms. https://www.hse.gov.uk/pubns/misc208.pdf

A containment level 2 laboratory should be restricted to authorised personnel, allow safe storage of microorganisms, have a microbiological safety cabinet for aerosol producing procedures, and all surfaces should be impervious to water and easy to clean. In addition, a containment level 3 laboratory should have HEPA filtered output air, be sealable for disinfectant and containment, have negative air pressure, and an observation window or video monitoring system. A containment level 4 laboratory must also be double filtered, accessible by air-lock and all work must be done in a sealed microbiological safety cabinet.

Organisms can be worked on at a containment level higher their hazard group, but never lower.

In addition to using a laboratory at the correct containment level, the following safety advice should also be followed at all times:

  • No eating, drinking, smoking, or applying makeup
  • No touching of face or mouth or other exposed parts of the body
  • No use of mobile phones or other electronic devices, including headphones
  • No open toed footwear
  • Gloves should be worn when handling biological material, or at all times in a laboratory of containment level 2 or above
  • Eye protection and masks should be worn when appropriate
  • A laboratory coat must be worn at all times, and it must be removed before leaving the laboratory
  • Long hair should be tied back
  • Place all waste in the appropriate waste/discard container
  • The work space must be kept clean and uncluttered
  • Hands must be washed thoroughly before leaving the laboratory

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This article is from the free online course:

Bacterial Genomes: Antimicrobial Resistance in Bacterial Pathogens

Wellcome Genome Campus Advanced Courses and Scientific Conferences