This page provides guidance for work with blood, blood products and other human tissue in research laboratories. It does not cover specific work with blood borne pathogens such as the human immunodeficiency virus (HIV) or hepatitis B virus (HBV).
The risk assessment should be specific for the procedures involved and take account of the nature and source of the samples to be handled. Of particular concern is the possible presence in the material of blood borne viruses (BBVs), most notably hepatitis B virus (HBV) and human immunodeficiency virus (HIV). However, other pathogens may be present and it is important to take account of these also. The key control measures when working with any blood and human tissues are maintaining good working practice standards and avoiding the use of sharps. Paying particular attention to these precautions will protect against the transmission of all blood borne pathogens by the percutaneous route.
Immunisation
All workers involved with handling unscreened blood, blood products and other tissues are recommended to have HBV immunisation (contact the University Occupational Health Advisor on Ext. 2026/4608).
Ethical considerations of other types of work are not considered here but should also be taken into account before starting work with blood or other human tissues.
It is also worth noting that blood is a particularly good medium for supporting the growth of a wide range of pathogens and contamination of the blood due to poor working practices may lead to potentially infective material (although these would be pathogens other than blood borne viruses).
The following describes the control measures required for handling primary materials.
All work on unscreened samples must be undertaken at a minimum of Containment Level 2 with the additional precautions given in Appendix 1 (PDF , 22kb). These precautions supplement the basic Containment Level 2 requirements and are to provide extra protection against percutaneous inoculation, and contamination of the skin, mucous membranes and working surfaces. The rigour with which these control measures are applied should be proportionate to the risk. For higher risk samples, for example those from a source population where the incidence of BBVs is greater than 1% (but the samples are not known or strongly suspected to carry BBVs or other pathogens, see below for further guidance on these), particular effort should be directed at segregating the work from general laboratory activities and avoiding all possibility of percutaneous inoculation.
In general, work at Containment Level 2 does not need to be confined to a safety cabinet unless there is reason to believe the specimen contains other pathogens that do require such containment. There is no substantive evidence that supports aerosol transmission of HBV and HIV. However where handling or processing may generate aerosols, large droplets or splashes, appropriate containment control measures must be adopted.
The notable exception to the above is for work on sputum samples and specimens of lung tissues. These must always be handled in a microbiological safety cabinet because of the potential risk from Mycobacterium tuberculosis, even if there is no reason to believe the pathogen is present. Similar samples known to be from patients suffering from tuberculosis must be handled at Containment Level 3.
Where it is known or strongly suspected (clinical indications) that blood borne hepatitis viruses, HIV or HTLV are present then the samples must be regarded as high risk materials and handled at a minimum in a derogated Containment Level 3 facility as described in Appendix 2 (PDF , 16kb) Gas cylinder check procedures (PDF , 15kb)unless any viruses that may be present are to be concentrated or propagated, either intentionally or otherwise, in which case full Containment Level 3 must be applied.
If other Hazard Group 3 pathogens are known or strongly suspected to be present in the material then the samples must only be handled in a full Containment Level 3 facility. This is a requirement under the COSHH Regulations. Under certain circumstances the viruses listed in the previous paragraph are exempted from this requirement allowing derogation of certain control measures. Some Hazard Group 3 parasites and enteric pathogens are also exempted, the University Biological Safety Adviser can be contacted for further advice if samples are likely to contain these.
If there is any likelihood that materials might contain Hazard Group 4 pathogens these must not be brought in to the University. The University Biological Safety Adviser can be contacted for further advice.
Since this guidance covers an extremely wide range of research activities throughout the University some generalisations have been made. If a researcher believes the detailed risk assessment of their particular project justifies undertaking the work at a lower level of containment to that described here, the University Biological Safety Adviser should be consulted. Help and advice on risk assessment can be given on a case by case basis and researchers are urged to contact the University Biological Safety Adviser at an early stage.
All specimen reception should be undertaken in the laboratory by trained workers. Arrangements should be made to ensure that untrained workers do not inadvertently handle samples particularly if these are received in the postal system.
Human blood and other body fluids and tissues are regarded as hazardous clinical waste and must rendered safe before disposal.
All human material must ultimately be disposed of by incineration. Yellow bags or containers should be used and deposited in the clinical waste bins, located in the Biology Stores Compound Area. All sharps (e.g. needles) must be disposed of in clinical waste sharp bins. Infected human materials, or those samples suspected of being infected should be autoclaved first followed by incineration. It is important that where a central autoclave facility is used (e.g. in Biology) that:
Immediately following any exposure the site of exposure e.g. wound or non-intact skin should be washed liberally with soap and water but without scrubbing. Antiseptics and skin washes should not be used - there is no evidence of their efficacy, and their effect on local defences is unknown. Free bleeding of puncture wounds should be encouraged gently but wounds should not be sucked. Exposed mucous membranes, including conjunctivae, should be irrigated copiously with water, before and after removing any contact lenses.
Particular care should be taken to ensure that others in the laboratory do not help with the clear up of accidental spillage (especially where there has been an accident that involves broken glass) if they are not aware of the potential risks and trained in safe working practices.
The source of any contamination (specimen, sample, material etc) should be clearly identified and retained for testing if necessary. Every effort should be made to ensure the confidentiality of persons potentially exposed to HIV as a result of an accident.
Accidents should be reported to and recorded by the person responsible for the work. The University Health and Safety Department and the Occupational Health Unit should be informed immediately in the event of any accident where exposure to a pathogen or infectious material may have occurred. A full accident record should be prepared and forwarded to the Health and Safety Department as soon as possible.
Under current guidelines samples can be tested for HIV only when informed consent has been given by the donor. The guidance provided above has been drawn up on the basis that testing is not feasible or practicable in many areas of research within the University. It is essential therefore that risk assessments take into account all available information and control measures are rigorously applied.
The HIV virus is not highly infectious nor particularly hardy and studies have shown that the occupational risk of exposure is low. In the event of infection, HIV can now be effectively controlled with drug treatment like many other chronic conditions.