• A problem currently facing building managers around the world is the health risk associated with buildings that have been vacant for months. Workers around the world are preparing to return to their office buildings, and need to provide clean and safe air and water.

    • Health risks from a building's air and water


      A problem currently facing building managers around the world is the health risk associated with buildings that have been vacant for months. Workers around the world are preparing to return to their office buildings, and need to provide clean and safe air and water.

      When modern buildings are left unattended and unoccupied for many months (or its systems are simply neglected) it's air and water systems can degrade in quality. Heating, ventilating and cooling (HVAC) systems, as well as water systems that have been in 'hibernation' can pose health hazards, such as legionella. 

      Legionella bacteria is the most common risk associated with unused water systems. If water supply is stagnant, legionella bacteria can multiply, which can cause an outbreak of Legionnaires' disease in people who have come into contact with the water. Legionnaires' disease is a type of pneumonia caused by the legionella bacteria. It is usually caused by individuals inhaling the bacteria from infected water, and is non-communicable. It's most common form of transmission is through breathing in droplets of the infected water. This could be through showers, or air conditioning units for large buildings.

      • Tips of how to avoid air and water health risks in returning to work

        • Prior to building's opening for use, all water systems should be properly flushed to clear any stagnant water (minimum 3 minutes)
        • Legionella testing is recommended to ensure none of the buildings water pipes have been infected by Legionalla bacteria during periods of disuse
        • Monitor temperature to ensure thermal gain in cold water is controlled and mitigated
        • Consider flushing the building twice weekly to simulate use and mitigate any risks of stagnancy


        Standards that can help


        The AS/NZS 3666 Series will be an important tool for buildings of all shape and size in the return to work. The AS/NZS 3666 Series includes four Standards that cover the various aspects of design, installation, commissioning, cleaning, operation and maintenance of air conditioning systems including cooling water systems. These four Standards can assist in managing air quality and risks such as legionella. 

        This Series includes the following titles:

        • AS/NZS 3666.1:2011: Air-handling and water systems of buildings - Microbial control - Design, installation and commissioning
        • AS/NZS 3666.2:2011: Air-handling and water systems of buildings - Microbial control - Operation and maintenance
        • AS/NZS 3666.3:2011: Air-handling and water systems of buildings - Microbial control - Performance-based maintenance of cooling water systems
        • AS/NZS 3666.4:2011:Air-handling and water systems of buildings - Microbial control - Performance-based maintenance of air-handling systems (ducts and components)


        Feel confident that your business is following best practice processes when returning to work. Discover a wide range of Standards to assist your safe return to the office.

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