The Australian National Animal Health Laboratory (A.N.A.H.L.), designed by the Department of Housing & Construction, in Geelong, Victoria (Fig. 56), is Australia's ultimate defence to protect our multi-million dollar livestock industry against disease. To effectively carry out its four main functions of diagnosis, training, research and vaccine development and testing, scientists at A.N.A.H.L. must work with potentially dangerous viruses. These viruses are controlled within the laboratory primarily by two specialised techniques, a 'box-within-a-box' configuration and a unique air handling system.

56 Model of the Australian Animal Healt Laboratory, Geelong, Victoria

The 'box-within-a-box' refers to a configuration of airtight cells in which a graduated system of negative air pressures is maintained to keep potentially hazardous materials inside the work area. Microbiological security is achieved through this configuration, which is three dimensional, using surrounding corridors, upper and lower floors and the external walls to create the innermost boxes where potentially dangerous material is handled. The work floor, comprising laboratories, large animal facilities and scientific support and services, is limited to one level of the five level building. To enter this floor staff must remove their street clothing, walk through a shower and wear special laboratory clothing. Shower entry and exit doors are airtight and interlocking to ensure that they cannot be opened simultaneously. For further security the laboratory was built using low shrinkage concrete and sealed precast panel construction.

The air handling system, in conjunction with the box-within-a-box configuration, captures and destroys air borne micro-organisms, which can be transported significant distances by air currents. Micro-organisms suspended in the air are removed by a process of high efficiency air filtration and, where necessary, heat sterilization. To establish a predictable flow of air, the air handling systems also create graduated negative air pressure regimes within the laboratory, which direct any leakage towards the innermost boxes, where air pressure is at its lowest. The control of the regimes is maintained by microprocessor-based electronic controllers, which were developed by engineers of the Department of Housing and Construction. Both the high efficiency air filter housings and microprocessor-based controllers are subject to world patents.

Australian Academy of Technological Sciences and Engineering