ACDP Classification of Pathogens

ACDP=Advisory Committee on Dangerous Pathogens report Categorisation of biological agents according to hazard categories of containment

Organisms are categorised by the ACDP

• Hazard Group 1 - A biological agent that is unlikely to cause human disease.
• Hazard Group 2 - A biological agent that can cause human disease and may be a hazard to employees; it is unlikely to spread to the communityand there is usually an effective prophylaxis or effective treatment is usually available.
• Hazard Group 3 - A biological agent that can cause severe human disease and presents a serious hazard to employees; it may present a risk of spreading to the community but there is usually effective prophylaxis or treatment available.
• Hazard Group 4 - A biological agent that causes severe human disease and is a serious hazard to employees; it is likely to spread to the community and there is usually no effective prophylaxis or treatment available.

Laboratory Facilities

The normal laboratories in the Department of Biology are usually only suitable, with some special precautions or adaptations, for work with Hazard Group 1 organisms. The following code of practice, based on that given by the ACDP, is recommended as a minimum for work on such organisms.

Containment Level 1

• The laboratory should be easy to clean. Bench surfaces should be impervious to water and resistant to acids, alkalis, solvents and disinfectants.
• If the laboratory is mechanically ventilated, it is preferable to maintain an inward airflow while aork is in progress by extracting room air to atmosphere.
• The laboratory must contain a wash-basin or sink that can be used for hand washing.
• The laboratory door should be closed when work is in progress.
• Laboratory coats or gowns should be worn in the laboratory and removed when leaving the laboratory suite.
• Personal protective equipment, including protective clothing, must be:
  • stored in a well defined place
  • checked and cleaned at suitable intervals
  • when discovered to be defective, repaired or replaced before further use
• Personal protective equipment which may be contaminated by biological agents must be:
  • removed on leaving the working area
  • kept apart from uncontaminated clothing
  • decontaminated and cleaned, or if necessary, destroyed
• Eating, chewing, drinking, taking medication, smoking, storing of food and applying cosmetics must not take place in the laboratory.
• Mouth pipetting must not take place.
• Hands must be disinfected or washed immediately when contamination is suspected, after handling viable materials and also before leaving the laboratory.
• All procedures must be performed so as to minimise the production of aerosols.
• Effective disinfectants shoul be available for immediate use in the event of spillage.
• Bench tops should be cleaned after use.
• Used laboratory glassware and other materials awaiting disinfection must be stored in a safe manner. Pipettes, if placed in disinfectant, must be totally immersed.
• All waste material which is not be incinerated should be disposed of safely by the appropriate means
• Materials for disposal must be transported in robust and leakproof containers without spillage.
• All accidents and incidents should be immediately reported to and recorded by the person responsible for the work or other delegated person.
• The effectiveness of the autoclave used for sterilisation must be monitored at regular intervals to ensure that all material is being effectively sterilised.

 Containment Level 2

Containment Level 2 is suitable for work with pathogens in Hazard Group 2. Laboratory personnel must receive suitable and sufficient information, instruction and training in working with agents in Group 2. A high standard of supervision of work should be maintained. The normal Biology Department laboratories are not usually suitable for use as category 2 labs and anyone planning the use of biological agents requiring such facilities must submit plans to the Biology DSA which show that all the conditions required can be met. The following information is an abbreviated version of the ACDP Report.

• Access to the laboratory is to be restricted to authorised persons.There should be adequate space (24 m3) in the laboratory for each person.The laboratory door should be closed when work is in progress.If the laboratory is mechanically ventilated, it must be maintained at negative pressure to atmosphere while to work is in progress (see ACDP report for more details and advice)

  The laboratory should be easy to clean. Bench surfaces should be impervious to water and resistant to acids, alkalis, solvents and disinfectants.

• There must be safe storage for biological agents.
• Laboratory coats or gowns, which should be back fastening, should be worn in the laboratory and removed when leaving the laboratory suite. Separate storage (for example, pegs) apart from that provided for personal clothing should be provided in the laboratory suite.
• Personal protective equipment, including protective clothing, must be:
  • stored in a well defined place
  • checked and cleaned at suitable intervals
  • when discovered to be defective, repaired or replaced before further use
• Personal protective equipment which may be contaminated by biological agents must be:
  • removed on leaving the working area
  • kept apart from uncontaminated clothing
  • decontaminated and cleaned, or if necessary, destroyed
• Eating, chewing, drinking, taking medication, smoking, storing of food and applying cosmetics must not take place in the laboratory.
• Mouth pipetting must not take place.
• Hands must be disinfected or washed immediately when contamination is suspected, after handling viable materials and also before leaving the laboratory.
• Laboratory procedures that give rise to infectious aerosols must be conducted in a microbiological safety cabinet, isolator or otherwise suitably contained.
• Effective disinfectants shoul be available for immediate use in the event of spillage.
• Bench tops should be cleaned after use.
• Used laboratory glassware and other materials awaiting disinfection must be stored in a safe manner. Pipettes, if placed in disinfectant, must be totally immersed.
• All waste material which is not be incinerated should be disposed of safely by the appropriate means
• Materials for disposal must be transported in robust and leakproof containers without spillage.
• All accidents and incidents should be immediately reported to and recorded by the person responsible for the work or other delegated person.
• An autoclave must be accessible from the suite.
• The effectiveness of the autoclave used for sterilisation must be monitored at regular intervals to ensure that all material is being effectively sterilised.
• There must be access to an incinerator for animal carcasses (see ACDP Report for more info).
• The laboratory should contain a wash basin near the laboratory exit. Taps should be of the type that can be operated without being touched by hand.
• Hands should be decontaminated immediately when contamination is suspected, after handling infective material and before leaving the laboratory. When gloves are worn, these should be washed or preferably changed before handling items likely to be touched by others not wearing gloves, for example telephones, paperwork. Computer keyboards and where practical, equipment controls should be protected by a removable flexible cover that can be disinfected.

Containment Measures for Containment Levels 2 & 3