Hot Works (Cutting / Grinding / Brazing) SWMS

Hot works covering oxy-fuel cutting, abrasive disc grinding, plasma cutting, brazing and silver soldering generate ignition sources capable of igniting combustibles up to 11 metres from the point of work, produce metal fume containing hexavalent chromium and manganese, and expose workers to UV-A/B/C radiation, molten slag and compressed gas hazards. Under WHS Regulation 2011 r291, hot works performed on construction sites constitutes High Risk Construction Work where there is a risk of fire or explosion from the ignition of flammable or combustible materials, mandating a documented Safe Work Method Statement before work commences. The SWMS must be prepared in consultation with workers, reviewed if controls fail, and kept until the work is completed (or for two years if a notifiable incident occurs). This template integrates the hot work permit system, defined combustible exclusion zones, fire watch protocols and post-work monitoring required by AS 1674.1, AS 1674.2 and the Model Code of Practice for Welding Processes.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Relocate componentry to an off-site fabrication workshop with engineered fume extraction, eliminating site hot works wherever prefabrication or mechanical fastening can substitute.
2. 2Elimination — Use cold-cutting methods (hydraulic shears, reciprocating saws, nibblers, bandsaws) on any work within 15 metres of stored flammables, fuel lines or sprinkler-impaired zones.
3. 3Substitution — Replace abrasive cutting with plasma or oxy-fuel where lower spark travel is needed, or substitute silver-bearing brazing alloys for cadmium-bearing alloys to remove acute toxicity.
4. 4Substitution — Substitute angle grinders with mechanically-fed chop saws or band saws fitted with coolant to reduce spark generation, vibration exposure and disc burst probability.
5. 5Engineering — Install fire-rated welding blankets (AS 1674.1 compliant to 1100°C), spark-proof screens and bunded slag trays; deploy LEV on-tool extraction capturing fume at 0.5 m/s face velocity.
6. 6Engineering — Fit flashback arrestors at both regulator and torch ends on oxy-fuel sets per AS 4603, and use only AS 4839-marked hoses with crimped (not jubilee-clipped) fittings.
7. 7Administrative — Issue a Hot Work Permit signed by the site supervisor before each shift, defining the 11 m combustible exclusion zone, fire watch duration (minimum 60 minutes post-work) and atmospheric test results.
8. 8Administrative — Conduct pre-start atmospheric monitoring (LEL, O2, CO) in any confined or semi-confined area, verify isolation of sprinklers and document fire watch personnel and extinguisher type/location.
9. 9PPE — Issue P2/P3 respirators (or PAPR for stainless/galvanised work per AS/NZS 1715), AS/NZS 1338.1 shade 5 cutting goggles, AS/NZS 2210.3 safety boots and leather welding leathers with spats.
10. 10PPE — Provide flame-resistant FR-rated coveralls (AS/NZS 4824), leather gauntlets, neck flash protection and ensure no synthetic base layers; replace PPE showing scorch, melt or arc burn damage immediately.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

On a four-storey commercial refurbishment, a mechanical services subcontractor needs to cut and braze copper chilled-water lines on Level 2 directly above a tenanted retail space still trading on Level 1. At the 6:45 am pre-start, the leading hand opens the Hot Works SWMS on a tablet and walks the three-person crew through the hazard register, pausing on spark travel and fume inhalation. Using the SWMS control matrix, the crew confirms they cannot eliminate the hot work (push-fit fittings unsuitable for the pressure rating), so they move to engineering controls: deploying a 2 m x 3 m welding blanket below the work zone, taping a spark-proof screen to the ceiling grid, and setting up a portable LEV with HEPA filter within 300 mm of the braze point. The supervisor issues the Hot Work Permit attached to the SWMS, nominating one worker as dedicated fire watch with a 9 kg dry chemical extinguisher and a CO2 backup, and confirms the sprinkler head within 3 m is bagged and tagged with an impairment notice. All four workers sign on. Mid-task, a gust through an open stairwell shifts spark fall outside the blanket footprint — the fire watch calls stop-work, the crew consults the SWMS dynamic-risk clause, repositions the screen and extends the blanket, re-signs the amendment field, and resumes. Post-work, the fire watch maintains observation for 60 minutes and logs clearance on the permit.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Code of Practice — Hazardous Manual Tasks

Frequently asked questions