Welding fumes pose a range of health risks, and a combination of engineering controls and respiratory protection is recommended to reduce exposures to as low as reasonably practicable.
Welding fumes are associated with respiratory illnesses such as metal fume fever, occupational asthma, chronic bronchitis and cancers.
In 2017, the International Agency for Research on Cancer (IARC) classified welding fumes as Group 1 – Carcinogenic to Humans, citing sufficient evidence for lung cancer.
In January 2024, Safe Work Australia (SWA) reduced the occupational exposure limit (OEL) for welding fumes from 5mg/m³ to 1mg/m³, an 80 per cent reduction. For extended shifts (eg 12 hours), the limit must be adjusted to account for longer exposure and reduced recovery time.
In addition, individual metals within the welding fume matrix have their own exposure limits. SWA has announced further reductions effective December 1, 2026.
Responsibility for controlling exposure lies with mine management, typically the senior site executive. It is their duty to ensure boilermakers are equipped with effective controls to reduce exposure to welding fumes, gases and particulates.
With the availability of engineering controls – including on-gun extraction, mobile filtered local exhaust and portable systems – most welding processes can be controlled at the source. Respiratory protection, such as powered air-purifying respirators (PAPR), should also be provided and maintained to ensure exposures are reduced to as low as reasonably practicable.
Several brands of on-gun or on-torch extraction systems are available. These systems capture fumes directly at the weld and filter them through extraction units. They are suitable for both metal inert gas (MIG) welding (flux core and bare wire) and tungsten inert gas (TIG) welding.
Mobile local exhaust ventilation (LEV) units are ideal for workshop environments and boilermaker bays. These systems filter fumes at the source and often include self-cleaning features to extend filter life. However, effectiveness depends on proper hood positioning; typically within 1–1.5 duct diameters of the fume source.
For field maintenance or confined spaces with poor ventilation (eg inside mobile plant, draglines, or screened fixed plant), portable LEV systems – often referred to as “pump and dump” – may be appropriate. These systems extract fumes and should be positioned to discharge the fumes to a safe location.
Most welding and allied processes can now be effectively controlled using a combination of LEV systems and respiratory protection. PAPR should be considered the industry standard.
Management must take proactive steps to prevent short- and long-term health effects. To assess welding fume exposures and evaluate control effectiveness, it is recommended to consult a qualified occupational hygienist. Support can be accessed through your organisation’s health and safety team, industry hygiene consultants, or professional bodies such as the Australian Institute of Occupational Hygienists (AIOH).
By Brett Young, certified occupational hygienist with the Australian Institute of Occupational Hygienists.
This feature appeared in the September-October edition of Safe to Work.