Close×

The AS/NZS 3666 standard series is an important tool to assist building managers and owners to prepare offices for thousands of returning workers post-lockdown.

Buildings that have been unoccupied during lockdown need to be properly prepared and safely flushed out before staff return, experts warned yesterday.

Potential dangers from systems being put into hibernation for an extended period can include health risks associated with air quality and mould, microbial growth, and corrosion in water systems.

When many Australians transitioned to working from home, buildings in metropolitan hubs and regional centres were left empty and their heating, ventilating and cooling (HVAC) systems put into hibernation.

Standards Australia chief executive officer, Adrian O’Connell, said as restrictions ease and workers return to the office, building systems must be considered as part of a safe return by building managers.

“It’s positive to see restrictions lifting and buildings occupied again. We know there is a lot to be considered when returning to a building, but it’s important environmental health is one that is not overlooked,” he said. 

The Australian and New Zealand Standard AS/NZS 3666 Air-handling and water systems of buildings - Microbial control standards series is a useful tool that helps manage building air quality and risk related to hazards like legionella.

Facility Management Association of Australia chief executive officer, Nicholas Burt, said precautions should be taken and regulations and standards considered when preparing the space for returning occupants.

Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH) CEO, Tony Gleeson, said there were two legionella outbreaks earlier this year proving that the risks associated with turning these systems back on are very real.

“The good news is there are practical steps that can be taken to safely flush them out,” Gleeson said.

Important steps to consider when flushing building systems can include:

Prior to facilities being opened for use, all water outlets should be flushed for at least 3 minutes each.

Prior to using appliances such as drinking water fountains, open fixtures to flow for at least a half minute.

Prior to start-up of any cooling water system, a cooling tower clean should be conducted and care must be taken to disinfect all system water.

Legionella testing may be conducted to ensure pipework has not been colonised by Legionella during periods of stagnancy.