Experts say buildings and offices that have been unoccupied during lockdown must be properly prepared and safely flushed out in order to prevent “very real” health risks.

Standards Australia (SA) says the potential dangers from systems being put into hibernation for an extended period can include risks associated with air quality and mould, microbial growth, and corrosion in water systems.

SA is encouraging employers to utilise the AS/NZS 3666  standard series as an important tool in assisting building managers and owners to properly flush out their systems and get buildings prepared for thousands of returning workers.

As many Australians transitioned into an extended period of working from home, a significant number of buildings were left empty with their heating, ventilating and cooling (HVAC) systems sitting idle.

CEO of Standards Australia, Adrian O’Connell, said it was positive to see restrictions lifting and buildings occupied again, but that there was a lot of environmental health considerations that needed addressing.

“The transition of working from home to back to the office will have its challenges for many organisations but having a prepared building does not have to be one of them.”

Australian Institute of Refrigeration, Air Conditioning and Heating CEO, Tony Gleeson, said legionella outbreaks were a real concern.

“A few months ago, many buildings were effectively put into hibernation and their HVAC systems shut down. With two legionella outbreaks already taking place earlier this year, 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.”

Standards Australia steps to consider when flushing building systems:

• 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 the 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.