Welding Fume Exposure SWMS

Welding fume is a complex mixture of metallic oxides, silicates and gases generated whenever a welding arc or flame melts base metal, filler material and any surface coatings present. The International Agency for Research on Cancer reclassified welding fume as a Group 1 human carcinogen in 2017, and Safe Work Australia subsequently lowered the workplace exposure standard for welding fume (not otherwise classified) to 1 mg/m³ TWA. Under WHS Regulation 2025 Part 4.1 and Regulation 347, any task that generates airborne contaminants capable of exceeding a workplace exposure standard requires the PCBU to identify, assess and control the hazard through a documented Safe Work Method Statement. This SWMS captures fume composition assessment, local exhaust ventilation selection, respiratory protection fit-testing, health monitoring triggers and emergency response — the controls that transform welding from an uncontrolled inhalation risk into a compliant, monitored activity. It is mandatory wherever workers weld, braze, cut or gouge metal indoors, in confined spaces, or on coated substrates regardless of duration.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

Hierarchy-of-controls order: elimination → substitution → isolation → engineering → administrative → PPE.

1. 1Elimination — substitute welding with mechanical fastening, bolting or adhesive bonding where structural and design specifications permit, removing the fume source entirely.
2. 2Elimination — strip paint, galvanising, oils and surface coatings from the weld zone (minimum 100mm either side) before striking an arc.
3. 3Substitution — select low-fume consumables (e.g. low-manganese wires, chromium-free flux) and switch SMAW to GMAW or laser welding to reduce fume generation rates.
4. 4Substitution — replace solvent-based pre-weld cleaners with aqueous degreasers to eliminate chlorinated hydrocarbon decomposition into phosgene at the arc.
5. 5Engineering — install on-torch fume extraction (capture velocity ≥0.5 m/s at the arc) or moveable LEV hoods positioned within 300mm of the weld, ducted to HEPA filtration per AS 3853.
6. 6Engineering — provide mechanical general dilution ventilation delivering minimum 10 air changes per hour in welding bays, with airflow direction away from the breathing zone.
7. 7Administrative — conduct atmospheric monitoring against Safe Work Australia exposure standards, implement job rotation, and schedule biological monitoring (urinary chromium, manganese) per AS/NZS 2865 health surveillance triggers.
8. 8Administrative — issue task-specific permits for welding in confined spaces, maintain a coatings register identifying base metal composition, and post fume hazard signage at all welding stations.
9. 9PPE — provide powered air-purifying respirators (PAPR) with P3/A2 cartridges for stainless or coated work, supplied-air respirators for confined spaces, fit-tested annually under AS/NZS 1715.
10. 10PPE — supply welding leathers, flame-resistant overalls, leather gauntlets and AS/NZS 1338.1-compliant welding helmets with auto-darkening filters; launder contaminated PPE separately to prevent take-home exposure.

Applicable Codes of Practice

Worked example

At the pre-start brief for a structural steel modification on a regional water treatment upgrade, the leading hand opens the Welding Fume Exposure SWMS on a tablet with the three-person welding crew. The job involves GMAW welding of galvanised handrail brackets to existing stainless steel walkway supports inside a partially enclosed pump house. Working through the hazard register, the crew identifies hexavalent chromium (stainless), zinc fume (galvanising) and confined-space CO accumulation as the dominant risks. The control matrix directs them to grind back the galvanising 100mm either side of each weld line, deploy the trailer-mounted LEV with flexible capture arm positioned within 250mm of the arc, and upgrade RPE from half-face P2 to PAPR with P3/A2 cartridges given the chromium exposure. The supervisor confirms each welder's PAPR fit-test is current, issues a hot work permit, and all three sign on to the SWMS. Two hours in, a welder reports the LEV arm cannot reach an overhead joint without obstructing the work. Rather than proceed uncontrolled, the supervisor pauses the task, returns to the SWMS, and applies the documented fallback control — supplied-air respirator plus increased general dilution ventilation via a portable axial fan. The change is annotated on the SWMS, re-communicated, and the crew signs the amendment before resuming.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• AS 1674 — Safety in welding; Welding Fume CoP

Frequently asked questions