Welding Fume in Mining Workshops

Mine site workshops handle heavy fabrication tasks including bucket rebuilds, chassis repairs, structural steelwork, and pipe fabrication. Flux-cored arc welding (FCAW) and shielded metal arc welding (SMAW) are the dominant processes. Workshop ventilation is often inadequate for the volume of welding performed, particularly in enclosed bay areas where multiple welders operate simultaneously.

Repair welding on haul trucks, excavators, loaders, and dozers occurs at breakdown locations across the mine site where fixed ventilation is unavailable. Welders work inside truck trays, excavator booms, and loader buckets where fume accumulates in semi-enclosed spaces. Natural ventilation varies with wind speed and direction, creating unpredictable exposure conditions.

Hardfacing wear-resistant alloys onto bucket lips, crusher liners, and chute liners generates fume containing chromium, manganese, and other alloying elements at higher concentrations than standard mild steel welding. Continuous hardfacing operations can run for full shifts, producing sustained high fume exposure for the welder and nearby trades.

Planned shutdowns at processing plants, mills, and crushing circuits concentrate large numbers of welders and boilermakers in confined plant areas for intensive repair campaigns. Multiple welding processes operating simultaneously in adjacent areas create cumulative fume exposure for all workers in the shutdown zone, including non-welding trades performing concurrent mechanical and electrical work.

Typical Worker Groups

Common similar exposure groups (SEGs) assessed for this sub-category.

Regulatory Context

Safe Work Australia's Welding Processes Code of Practice (2019) requires all welding fume to be captured at source or controlled below the WES using engineering controls as the primary measure. From 1 December 2026, the WES for welding fume (not otherwise specified) reduces from 5 mg/m³ to 1 mg/m³ inhalable fraction. This five-fold reduction will require mining operations to invest in local exhaust ventilation systems for workshop welding and on-torch extraction for field welding. Health monitoring is required for workers with significant exposure to welding fume, including respiratory function testing. State mines inspectorates incorporate welding fume compliance into maintenance and workshop inspection programmes.