Faculty of Science and Engineering

Safety in Microbiology

The organisms that you will handle in the laboratory are regarded either as non pathogenic (non disease-producing) e.g. brewers yeast and lactobacilli which cause souring of milk, or have a low probability of initiating an infection unless introduced in large numbers into the body by contamination of open cuts on the skin, splashing into the eyes or swallowing. However, potentially more hazardous organisms are used for research and other purposes in the School, and such cultures will be located in the microbiology preparation room (H617) and adjacent laboratories.petri dishes

There is a very slight risk of cultures used for teaching being mislabelled or contaminated with either organisms used for research or by organisms originating from teaching or technical staff who may have an asymptomatic infection. This risk, however slight, cannot be ignored.

All cultures that you handle must be regarded as potentially hazardous.

To minimise the risk of accident or spillage, the following rules must be observed by all people working in the microbiology labs, even if they are only reading results.

  1. Briefcases, bags and outdoor coats must be placed in a locker. (These cannot be left outside the labs)
  2. A clean white coat must be worn at all times and this must be buttoned up; it should be free from major holes and tears. The coat should be removed at all times when leaving the laboratory.
  3. Long hair should be tied back so that it does not fall into open culture vessels.
  4. Watches and jewellery should be removed.

Remember it is the responsibility of the person in charge of the class to decontaminate the personal belongings of any student if they come in to contact with the cultures in use in the lab. This may only be achieved by exposure to steam or immersion in disinfectant. Such treatment may obviously damage watches, articles of clothing, books or briefcases and the University could not accept liability if the action was necessitated by carelessness or disregard for safety instructions or other instructions, either written or verbal, regarding the handing of cultures.

  1. Hands should be washed after all lab work and the bench swabbed with disinfectant.
  2. No cultures or contaminated liquids should be poured down the sink.
  3. No specimen, slides, cultures or other items may be removed as souvenirs.
  4. All contaminated items should be discarded in the disinfectant jars, autoclave bags or placed on the trolley designated for the purpose; they do not go into the waste bins.
  5. All containers must be appropriately labelled with waterproof marker pens.
  6. Any spillages of contaminated liquid, either on the skin or on inanimate objects or work surfaces, must be swabbed with disinfectant and cotton wool. Larger spillages must be brought to the attention of the person in charge of the lab.
  7. Contamination of cuts and grazes, swallowing or introduction of cultures into the mouth or eyes must be reported immediately.

Many accidents or spillages result from the following practices which are best avoided.

test tubes

  1. The use of unsuitable or malfunctioning pipette fillers. Ensure that you know how to use a pipette filler and that it is working properly before you begin.
  2. Incompletely labelled or unlabelled containers.
  3. Attempting to hold too many test tubes in the hand at once. Ensure that you have an appropriate test tube rack.
  4. Walking around the lab holding containers of contaminated material; keep these on the bench as much as possible.
  5. Removing rubber teats from pipettes tends to squirt the last drop of liquid out of the pipette. Ensure that it is pointing into a disinfectant jar before removing the teat.
Any student who fails to abide by any of the above regulations will be dismissed from the laboratory immediately, and may consequently fail that module.