What is an airborne contaminant?
Work processes can release dusts, gases, fumes, vapours, fibres or mists. These airborne contaminants may be invisible but can cause serious harm and pose health and safety risks.
Contaminants can be released into the air when using hazardous chemicals or carrying out work processes such as those involving:
- rotating tools and parts, for example, sanders, circular saws, routers, lathes, drills
- hot processes, for example, furnaces, soldering, brazing, welding
- falling material (solids, liquids or powders), transferring powders, mixing
- spraying, painting, or abrasive blasting
- fracturing of solid material, for example, crushing rock
- abrasion, for example, sanding, grinding, polishing, fettling
- cleaning and waste handling, for example, sweeping or compressed air clean up.
Examples of airborne contaminants
Airborne contaminants can be produced by a wide range of processes or tasks in the workplace. Some examples of common airborne contaminants and their form are:
- gas – carbon monoxide and carbon dioxide
- vapour – acetone, ethanol, chloroform, styrene, petrol
- fibres – asbestos and glass
- mist – solution being sprayed, for example, paint, steam and electroplating baths
- fume – solder or welding fumes
- dust – flour dust, concrete, cement or wood dust generated by grinding, cutting, crushing, drilling, etc. and silica from stone cutting.
Health effects
The respiratory system can remove some contaminants through a series of defence mechanisms, but breathing in high levels of contaminants or low levels over a long period can overwhelm these defences, resulting in disease.
Several factors affect the impact of contaminants. These include particle size, chemical composition, the amount in the air, and the characteristics of the person exposed.
Exposure to certain airborne contaminants has the potential to cause or worsen a wide range of serious respiratory diseases, including:
- asthma
- cancers of the respiratory system
- chronic obstructive pulmonary disease (also called COPD)
- mesothelioma
- silicosis.
Many respiratory diseases from exposure to dusts, gases, vapours, smoke and fumes may take a long time to develop. Airborne contaminants can also affect other parts of the body, including specific organs, eyes, nose, mouth and skin.
Work health and safety duties
Under the work health and safety laws, employers and other duty holders, as a person conducting a business or undertaking (PCBU), have a duty to ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the workplace exposure standards.
Workplace exposure standards
Workplace exposure standards (WES) are the maximum level of an airborne contaminant that most (but not all) people can be exposed to without harm to their health.
From 1 December 2026, workplace exposure standards will be replaced by the workplace exposure limits (WEL). This change includes revision of a significant number of exposure standards with some resulting in a reduction of the limit following the outcome of a health-based review conducted by Safe Work Australia.
As a PCBU, you must make sure that workers are not exposed to airborne contaminants or substances above the exposure standard, or the workplace exposure limit as of 1 December 2026.
Even if a substance has no set limit, it can still be harmful. Check global limits and reduce exposure as much as possible.
Under the WEL review, some substances have had their WES removed where a safe level is not able to be determined. In particular, 32 chemicals will be deemed Non-Threshold Genotoxic Carcinogens and will not have a WEL. PCBU’s must eliminate the risk of exposure to these chemicals, or where elimination is not possible then reduce exposures to as low as reasonably practicable.
Learn more about workplace exposure standards or limits.
Check the atmosphere
Air monitoring must be carried out to determine the concentration of a substance or mixture in the air where the PCBU is not certain on reasonable grounds whether the concentration of the substance exceeds the exposure standard, or where it is necessary to determine if there is a risk to health. Records of monitoring must be kept for 30 years. Results must be given to anyone who was personally monitored or who might have been exposed.