Biological safety

Certain departments of the University often handle biological materials with a known risk to the investigator, fellow workers and the environment.

For this reason the University has safety guidelines in place that are to be observed at all times.

These guidelines are outlined below.

The following areas of research are classed as potentially biohazardous


  1. Cell culture involving cell lines of human or primate origin. This includes EBV-transformed cell lines.
  2. Cell culture involving “hybridoma” cell lines especially those derived from interspecies fusions.
  3. Growth of tumours in immunosuppressed xenogeneic hosts, such as “nude” mice.
  4. The handling of human blood, serum and tissue specimens.
  5. Experiments using bacteria, viruses and parasites, grown in vivo or in vitro.
  6. FACS analysis of human materials.
  7. Experiments involving recombinant DNA.

Never use cells from staff or their relatives to generate cell lines, due to the high risk of re-exposure to histocompatible transformed lines.

General Guidelines for Working with Biohazardous Material


  1. Follow Departmental Safety Rules.
  2. Treat all human blood and body fluids, bone marrow, tissue culture and tissue specimens as if they were contaminated with an infectious agent.
  3. Use the appropriate containment conditions (eg, Class II hood for handling human material or a pathogen) for your experiment.
  4. Disposable gloves must be worn when handling biohazardous materials. They must be disposed of into biohazard waste containers immediately upon conclusion of task. Care should be taken to prevent contaminated gloves coming in contact with laboratory furniture, doorknobs, telephones etc.
  5. Wherever possible use disposable pipettes and tubes rather than washing glassware.
  6. Contain hazardous material in biohazard bags for autoclaving. See the Safety Officer if you are unsure that contaminated material has been properly contained. Contaminated material must be carried in a leak-proof container when being transported out of the laboratory.
  7. Contaminated recyclable glassware and equipment must be sterilised by autoclaving before being washed. Equipment that cannot be autoclaved must be disinfected. 7% Hypochlorite solutions can be diluted to a concentration of 0.07% (1:100) to make a suitable decontaminating solution (approx. 700 ppm). Available chlorine, the active element, will decrease in strength in dilute solutions. Any diluted hypochlorite solutions should be made up immediately prior to use. Allow at least 30 minutes contact for proper decontamination.
  8. The 30 minute holding time allows complete destruction of bacteria and bacterial spores. A very effective disinfectant can be made by mixing a solution of 700 ppm available chlorine with 0.7% nonionic detergent. Discard waste down a fume hood sink and rinse well.
  9. Note that quaternary ammonium compounds, phenolic compounds and ethanol are not effective against bacterial spores and that ethanol is slow in its germicidal action.
  10. Avoid techniques which have a high potential for creating aerosols (eg, sonication, vortexing, blowing out pipette contents, centrifuging unsealed tubes). Any aerosol generating manipulation must be carried out in a biohazard cabinet. Sealed tubes must be used for centrifuging hazardous materials using sealed rotors or buckets to minimise contamination in the event of tube failure.
  11. Institute a regular routine of cleaning and decontaminating bench tops and surfaces of hoods where biohazardous material is handled, by wiping with an appropriate disinfectant such as 70% ethanol. This should be done at least once a day. At all times, keep laboratory and bench tops clean. This especially applies to hood surfaces and ancillary rooms such as the cold room. Keep the floors clear. The cleaners mop and polish the floors of laboratories at regular intervals.
  12. Segregate and dispose of all biohazardous waste correctly. Take appropriate precautions with contaminated sharps and needles. DO NOT RECAP NEEDLES. DO NOT SEPARATE NEEDLES AND SYRINGES. Dispose of intact needle and syringe by placing in approved sharps container. Autoclave all other waste before placing in appropriate waste container.
  13. Clearly label all biohazardous material and remove biohazardous labels from material that has been decontaminated. Do not use containers with printed biohazardous labels (eg, autoclave bags, sharps bins etc.) for other purposes.
  14. Cupboards, refrigerators and freezers used for storing biohazardous material should be clearly labelled indicating the nature of the material stored within, and carry the universal biohazard sign.
  15. Report any accident or any spillage of biohazardous material immediately to the Departmental Safety Officer.
  16. Report any suspected infection immediately to the laboratory head and to the Departmental Safety Officer.

Containment Facilities - Class II Hoods


  1. Risks caused by infectious organisms are reduced by handling these agents in specially designed Class II Hoods.

    Only Class II hoods provide both containment and a sterile work zone. Never use a crossflow hood for handling biohazardous material.
     
  2. Work as far back in the hood as is comfortable to ensure that proper containment of hazardous work. Be aware that some of the Class II hoods in the Department do not comply with modern containment standards. These hoods have been tested and comply with modified tests that assume work is carried out at least 75 mm from the air curtain. Work in these hoods must therefore never be allowed to come within 75mm of the front air grill.
  3. All waste generated in these hoods must be decontaminated by autoclaving or by treatment with chemical disinfectant prior to disposal. Be sure that approved biohazard bags are used to contain hazardous material.
  4. Decontaminate all surfaces in hoods after use by swabbing with 70% ethanol.
  5. Flush hoods by continuing operation for ten minutes after use.
  6. Turn UV light on to sterilise between uses.
  7. Always leave hoods clean and tidy after use.

Biohazardous Waste Disposal


  1. All material must be autoclaved before following the disposal rules for tissue culture materials.
  2. The following material must be autoclaved before disposal:

a) all material from human origin

b) all material that has come in contact with a known pathogen

c) all material that has come in contact with or used in recombinant DNA work.

  1. All material that is contained in an autoclavable bag and contains sharps (ie. pasteur pipettes) must be labelled as containing sharp material.
  2. Used gloves should never be discarded in ordinary rubbish bins.