When handling blood specimens, what is the leading biological hazard for laboratory personnel?

Background

All laboratory biological specimens should be regarded as hazardous and may be viewed as falling into one of the following categories:

Routine specimens for which there is no history suggesting they present an increased biohazard.

Infected specimens regarded as possibly presenting a high biohazard include specimens from patients whose clinical history indicates the possibility of the following:

• Viral haemorrhagic fevers
• Hepatitis B
• Human Immunodeficiency Virus disease (A.I.D.S.) and cultures of the following organisms:
  • Human Immunodeficiency virus
  • Briella (all species)
• Mycobacterium of all species
• Salmonella typhimurium.

These specimens and cultures must have a biohazard label affixed to the specimen container.

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Protective clothing

Always wear protective clothing, particularly disposable gloves. When handling samples and spilled material, masks may be required if there is the potential for aerosol production.

Gloves should be removed in such a way that the skin does not come into contact with the external surface of the glove. At regular intervals the correct procedures should be demonstrated by senior laboratory personnel.

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Equipment

All glassware contaminated with fluid should be discarded into a strong solution of sodium hypochlorite (approximately 0.5 per cent available chlorine). Disposable apparatus should be discarded into a wet strength bag that is autoclaved prior to being sent for incineration. (Refer to the Waste management safety for more information.)

Centrifuges used for spinning body fluids should have a sealed rotor and/or sealed buckets with transparent lids which allow staff to see if a breakage has occurred. In the event of a breakage during centrifugation, the whole bucket can be autoclaved before the lid is removed.

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Human biological specimens in laboratory practical classes

In some laboratory practical classes, exercises using blood have been devised where the blood samples used are obtained from staff or students by venepuncture or a finger prick or from patients with diseases of special interest. Other body fluids (such as urine and saliva) may be used and obtained from students and patients.

If patient blood samples are used, the samples should be screened just as blood would be at the blood bank (viz: tested for syphilis, Hepatitis B and HIV) prior to use in the practical class.

If student blood samples are used, individual students should, if practicable, use their own blood.

Note: Students or staff who know they are HIV-positive should be requested not to participate in these exercises.

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Spills

If any body fluid is spilled, it should be cleaned up immediately with a liberal quantity of 70 per cent alcohol followed by a strong solution of sodium hypochlorite (approximately 0.5 per cent available chlorine).

Laboratory coats contaminated with body fluid must be placed in a chlorine bath for 30 minutes.

Material used to clean up the spill must be disposed of separately via autoclaving. (Refer to Waste management safety.)

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Sharps protocol

Precautions

Infectious diseases may be spread by 'sharps', the collective term used for infected needles or other sharp implements that cause injury. Accordingly, every precaution must be taken to prevent such accidents.

Needles and syringes are to be discarded only into approved containers of the BUNZYL (needles only) or SHARPSAFE types. These containers should:

• be puncture-resistant, leak-proof, shatterproof and able to withstand heavy handling
• be clearly labelled and distinctively coloured displaying the universal biohazard label, and instructions for use. The nature of the contents should be clearly marked on the exterior
• be easy to assemble and stack so as to conserve storage space
• have the opening accessible, safe to use and designed so that it can easily and safely be determined how full the container is. The container should be sealed when full or ready for disposal and capable of being handled with no danger of contents spilling or falling out.

Never attempt to replace the cap on a needle after use as this may lead to a 'needlestick' injury.

Sharps containers should be disposed of in accordance with local guidelines.

Procedure following a 'sharps' injury

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What is biological hazard in laboratory?

How do you handle biological specimens?

What are biological hazards in healthcare?

How should samples and specimens be handled and collected?