Office air quality can be affected by various sources, including odors and microbiological or chemical contaminants. The following are some recommendations from WorkSafe's Office Health and Safety guide for employers.
Air Conditioning
In most offices, air-conditioning systems play a vital role in maintaining air quality. Air-conditioning systems contribute to air quality levels by drawing in outside air, filtering and adjusting its temperature or humidity, circulating it throughout the building, and expelling a portion of the air while replacing it with fresh air.
Employers in enclosed workplaces must ensure air movement remains comfortable, typically between 0.1 and 0.2 metres per second (m/s).
Guidelines for appropriate air quality standards in office environments are outlined in Australian Standards, particularly:
• AS 1668.2:2024: The use of ventilation and air conditioning in buildings, Part 2: Mechanical ventilation in buildings
• AS 1668.4-2024: The use of ventilation and air conditioning in buildings, Part 4: Natural ventilation of buildings.
AS 1668.2:2024 specifies a minimum outdoor airflow rate of 10 litres per second (L/s) per person, based on a net floor area of 10 m² per person. For office areas with higher occupancy, ventilation should be increased to maintain this recommended airflow rate per person (10 L/s for each person in the space).
Identifying and assessing air quality issues
To address air quality concerns, employers should engage a qualified professional to assess air quality and implement their recommendations. Workplaces must be adequately ventilated with fresh, clean air that is sourced from outside, uncontaminated by flues or other outlets, and circulated effectively throughout the workspace.
Air conditioning systems should maintain a comfortable indoor environment by:
• providing a comfortable environment for air temperature, humidity and air movement.
• preventing the excessive accumulation of odours.
• reducing the levels of respiratory by-products, especially carbon dioxide, and other indoor contaminants that may come from work activities.
• supplying an amount of fresh air to the workplace, exhausts some of the stale air, and filters and recirculates some of the indoor air.
• being regularly serviced and maintained in accordance with the manufacturer’s instructions.
Buildings should be regularly cleaned to maintain air quality, including frequent vacuuming of carpets and removal of dust.
Employers should also guide employees to minimize air quality issues by avoiding the use of odour-producing items like fragrance oils and incense, which can spread through the air conditioning system. Employees should be mindful of cooking odours and use exhaust fans where available. Additionally, they should promptly report any leaks or damp areas to ensure a healthy indoor environment.
Smoke
Bushfire smoke and smoke from planned burns can pose health risks, particularly to people with chronic conditions, older adults, and pregnant women.
During smoky conditions, employers should verify the source of the smoke by checking with Forest Fire Management Victoria or calling the VicEmergency Hotline at 1800 226 226 and follow the relevant advice.
To minimize the impact of smoke:
- Limit physical activity.
- Stay indoors with windows and doors closed.
- Set air conditioning systems to recycle or recirculate air.
- Consider temporarily leaving the area if conditions worsen.
- Seek medical advice for anyone experiencing smoke-related symptoms.
Indoor air quality can still be affected during bushfires due to HVAC systems drawing in outdoor air, so employers should take steps to mitigate exposure.
Ozone
Photocopiers release small amounts of ozone gas, which, in high concentrations, can irritate the eyes, lungs, throat, and nasal passages. However, under normal operating conditions, ozone levels from photocopiers are typically too low to cause symptoms like itchy eyes or illness.
The ozone concentration near an operator depends on factors such as the amount of ozone emitted, its rate of decay, room size, temperature, and ventilation. Persistent odours from modern copiers or fax machines often indicate insufficient ventilation.
More information can be found on Safe Work Australia’s Workplace Exposure Standards for Airborne Contaminants.
Ventilation for multiple machines
Photocopiers, printers, and fax machines are often placed in the same room or area. To prevent atmospheric contaminants from reaching harmful levels, keep the door open if possible. In open spaces, ensure proper ventilation and airflow.
If noise is a concern or the door is closed for other reasons, assess the impact on ventilation and make adjustments as needed. When ventilation is sufficient, the heat generated by standard office equipment should not affect the workspace.
Airborne diseases
Working in indoor spaces such as offices increases the risk of catching airborne illnesses. If someone with an infection has been in the area, viruses can remain in the air, particularly in:
- rooms with poor air circulation
- spaces where air doesn't move or flow properly
Making sure your workplace has good fresh air flow is important, as it helps reduce the concentration of virus particles in the air. This fresh air circulation makes it less likely for infections to spread between people.
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There are several ways employers can maintain proper ventilation in the workplace:
Through natural ventilation, which involves fresh air flowing in through windows, doors, and vents. Keep in mind that this method's effectiveness depends on:
- The size of window and door openings
- Current weather conditions, including wind patterns Note that natural ventilation alone may not be enough to quickly clear the air of virus particles.
Through mechanical ventilation, which uses powered systems (HVAC - heating, ventilation, and air conditioning) to bring fresh outdoor air inside the building.
Or by using both natural and mechanical ventilation together.
To improve workplace ventilation, employers can take these steps:
- Increase how quickly air is supplied to spaces
- Bring in more fresh air from outdoors
- Minimize or stop recycling air through HVAC systems
- Use better filters in HVAC systems when recycling air (as long as this doesn't reduce airflow)
- Schedule regular HVAC maintenance, including filter replacements
Portable HEPA Air Cleaners Portable air cleaners with HEPA (high-efficiency particulate air) filters help reduce:
- Virus particles in the air
- Other airborne contaminants
While these units can be helpful, they don't replace proper ventilation. Consider using HEPA units in:
- Areas where good ventilation is difficult to achieve
- Spaces with higher transmission risks
Risk Assessment and Planning Employers should conduct risk and ventilation assessments to determine:
- Which ventilation strategies best suit each space
- Whether air cleaners are necessary
- The best placement and maintenance plan for air cleaning units
To ensure proper ventilation, employers should:
- Collaborate with building owners/managers on ventilation improvements
- Consider consulting experts like occupational hygienists or ventilation engineers
- Keep all heating and cooling systems well-maintained through regular servicing
Important Health Considerations Remember that better ventilation is just one part of infection control - it doesn't eliminate all risks from droplets or contaminated surfaces.
Another serious health concern is Legionnaires' disease, a severe form of pneumonia caused by legionella bacteria. People can get infected by breathing in contaminated water droplets from:
- Air conditioning cooling towers and warm water systems
- Spa bath mists
- Potting mix aerosols
To reduce legionella exposure risk, employers must ensure:
- Air conditioning systems are properly designed and maintained
- Regular cleaning of water systems, including:
- Air conditioning units
- Cooling towers
- Pools
- Baths and showers
Under the Public Health and Wellbeing Act 2008, Victorian workplaces must:
- Register all cooling towers
- Implement a risk management plan
- Conduct regular system testing and maintenance
More Information
From our website:
From WorkSafe Victoria:
- Work-related stress – poor environmental conditions | WorkSafe Victoria
- WorkWell Toolkit: Poor environmental conditions | WorkSafe Victoria
Other sources:
- Managing the risks from air pollution: Advice for PCBUs | Safe Work Australia
- Ventilation at work | SafeWork NSW
- Indoor Air Quality (IAQ) | US EPA
- Handbook: Indoor air quality
Published January 2025