ABC of Safety in the Biological Sciences




ACCESSIONING (Specimen recording)

A sound method for handling and recording the receipt of each specimen in the laboratory is of paramount importance and forms the basis of safe practice within each laboratory.

The specimen can consist of any animate or inanimate object or substance and can come in many different forms, e.g. a chemical, a liquid, a rock sample, an animal or animal remains, a plant, human body fluid or human body tissues.

Many laboratories use a mainframe or personal computer for their data base or laboratory information management system, while others may rely on book-keeping methods. Whatever method is used for recording receipt of specimens, a suitable protocol needs to be developed which eliminates the possibility of accessioning errors occurring and establishes safe specimen handing techniques.

Errors and hazards associated with accessioning are:
1. Labelling errors.
2. Specimen related hazards.

  • General
  • Medical and biology laboratories.
3. Container and request form contamination.

Labelling errors
A mix up of specimens could have serious consequences in any biological sciences laboratory. There is the possibility of staff who subsequently handle the specimen sustaining permanent damage to themselves as a result of a specimen mix up. There is also the possibility that a patient might receive inappropriate therapy as a result of a specimen mix up. One of the more common accessioning errors occurs when specimen lids are labelled rather than specimen containers. Lids can become transposed from one container to another resulting in a mix up of specimens.


Always ensure that the data on any specimen container which is received for testing matches the data on an accompanying request form.

Specimen hazards
i) General.
The golden rule is :


Many of the specimens received in biological sciences laboratories are in themselves potentially hazardous, especially specimens of human material submitted to medical laboratories for testing. The majority of these specimens are sent for diagnosis of a patient's disease state and may contain bacteria or virus particles which are contagious. Other specimens may be very toxic, inflammable or even radio­active. The person accessioning specimens must be made aware of the potential danger involved to themselves and/or the environment from the specimen being handled in their laboratory. If the golden rule is ALWAYS followed, the likelihood of a contamination occurring to staff or the environment from a biological sample will be remote.

ii) Medical and biology laboratories.
Staff employed in medical and biology laboratories face additional hazards in that biological specimens received in these laboratories are often contained in substances that are themselves toxic or hazardous. For example, in the histopathology laboratory where human body tissues are received for examination, processing and diagnosis, the body tissues are generally received in a formalin solution which fixes the tissue in a life­like form.

Formaldehyde from which this formalin solution is prepared is very toxic. It is also a strong eye, skin and mucous membrane irritant and is a potential carcinogen (see Formalin in the Chemical list).


Container contamination
If the specimen container or the request form become contaminated by a biological specimen, in order to reduce the risk of further contamination to staff or working surfaces the contaminated specimen should be placed into a sealed plastic bag until it is required. A request form which has been contaminated by leakage from a specimen container should be placed into a sealed plastic bag, photocopied through the plastic bag and then discarded. The uncontaminated photocopy can then be used in its place.



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