Welding, the process of joining metal parts together, is necessary in many mining operations. However, dangerous fumes are released in the process. These ‘welding fumes’, a complex mixture of gases and particles, are formed when a metal is heated above its boiling point and its vapours condense. Prolonged exposure to these welding fumes above Occupational Exposure Limits¹ can lead to adverse health outcomes, such as organ damage (e.g., lung and kidney) and cancer (e.g., lung, larynx, and urinary tract). Welding fumes were classified by the International Agency for Research on Cancer as a Group 1 Carcinogen in 2017.²   

Workers who weld and gouge on ‘slag pots’³ at our Olympic Dam operation, South Australia use respiratory protection, however it was identified that additional controls may be available. In 2021, our Smelter Maintenance and Occupational Hygiene teams together started to explore and implement improved controls with the aim of achieving significant welding fume exposure reductions. Their collaboration was driven by the following critical principles:  

• We are committed to reducing occupational exposures to as low as reasonably practicable.  
• We want to create a safe and healthy workplace and protect workers from long latency disease. 
• We want workers’ exposures to be consistently identified and controlled. 
• Doing what is right and doing what we say we will do.  

Implementing these principles involved undertaking an initial risk assessment, conducting broad consultation with key stakeholders, including welders, and finally, introduction and implementation of the identified engineering controls. 

Control effectiveness testing has been carried out by the Occupational Hygiene team, which indicates that significant welding fume exposure reductions have been achieved. Thanks to these engineering efforts, the total welding fume exposure for affected workers at Olympic Dam (those who weld and gouge on ‘slag pots’) has halved in concentration. Due to the success of this project, controls are now being trialled in some of our other operations, including WAIO at Mining Area C.   

A new local extraction ventilation system which was introduced

1 An Occupational Exposure Limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air.
2 A ‘Group 1’ classification means there is sufficient evidence of carcinogenicity in humans. 
3 Slag pots are large containers used for collecting molten byproducts of smelting and refining processes, for transportation and deposit at relevant disposal areas