MICROBIOLOGY

The basic approach to working with microorganisms is to regard them all as potential pathogens and to handle them with standard microbiological techniques to minimise the risk to laboratory staff and the environment.

AS 2243.3:2002 Safety in Laboratories Part 3: Microbiological aspects and containment facilities outlines requirements for laboratories handling microorganisms. The Standard specifies different containment requirements for facilities depending on the type of microorganisms being handled. A complete copy of the Standard can be accessed via the University Library database under Standards Australia.

The World Health Organisation (WHO) suggests each country draw up risk groups according to the microorganisms encountered within its boundaries. The following classification has been drawn up for Australia and New Zealand and is based on the pathogenicity of the agent, the mode of transmission and host range of the agent, the availability of effective preventive measures, and the availability of effective treatment.

a) Risk Group 1 (low individual and community risk) – a microorganism that is unlikely to cause human, plant or animal disease.

b) Risk Group 2 (moderate individual risk, limited community risk) – a pathogen that can cause human, plant or animal disease, but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment; laboratory exposures may cause infection, but effective treatment and preventive measures are available, and the risk of spread is limited.

c) Risk Group 3 (high individual risk, limited community risk) – a pathogen that usually causes serious human or animal disease and may present a serious hazard to laboratory workers. It could present a risk if spread in the community or the environment, but there are usually effective preventive measures or treatment available

d) Risk Group 4 (high individual and community risk) – a pathogen that usually produces life-threatening human or animal disease, represents a serious hazard to laboratory workers and is readily transmissible from one individual to another. Effective treatment and preventive measures are not usually available.


A comprehensive list of organisms classified into their Risk groupings is provided in AS2243.3. The Risk groupings include lists of bacteria, fungi, viruses and prions.

A complete copy of the Standard can be accessed at
A complete copy of the Standard can be accessed via the University Library database under Standards Australia. Pages 22-33 provide listings of organisms within Risk Groups.

AS2243.3 specifies four levels of physical containment for laboratories.

PHYSICAL CONTAINMENT LEVEL 1 (PC1)
A Physical Containment Level 1 laboratory is suitable for work with microorganisms where the hazard levels are low, and where laboratory personnel can be adequately protected by standard laboratory practice. The organisms used are not known to cause disease in healthy adults (i.e. organisms in Risk Group 1). Work may be carried out on the open bench. Specimens that have been inactivated or fixed may be handled in a level PC1 laboratory.

PHYSICAL CONTAINMENT LEVEL 2 (PC2)
A Physical Containment Level 2 laboratory is suitable for work with material likely to contain microorganisms which may be present in the community, where the microorganism may be associated with animal, plant or human disease of moderate severity (i.e. organisms in Risk Group 2). With good microbiological techniques, work with these agents may be carried out on the open bench. If there is a significant risk from the production of aerosols, a biological safety cabinet must be used.

PHYSICAL CONTAINMENT LEVEL 3 (PC3)
A Physical Containment Level 3 laboratory is suitable for work with indigenous or exotic microorganisms, and where there is a risk of serious infection to humans, animals or plants (i.e. organisms in Risk Group 3). A Physical Containment Level 3 laboratory provides safeguards to minimise the risk of infection to individuals, the community and the environment.
The University currently has no certified PC3 facility.

PHYSICAL CONTAINMENT LEVEL 4 (PC4)
A Physical Containment Level 4 laboratory is suitable for work with dangerous microorganisms that pose a high individual risk of life-threatening disease and may be readily spread to the community (i.e. organisms in Risk Group 4). A Physical Containment Level 4 laboratory is a facility situated in a building separate from other laboratories or constructed as an isolated area within a building.
The University has no PC4 facilities.

Last Updated: 30th March 2006
Page Maintained by: Jenny Dawkins