Mobile / On-Site Field Abrasive Blasting SWMS

Mobile and on-site field abrasive blasting is open abrasive blasting carried out in the field — on structures, plant, bridges, tanks and steelwork — rather than in an enclosed blast room. It is routinely high risk construction work under the NSW WHS Regulation 2025 because field blasting is carried out at height with a risk of a fall of more than 2 m, on or near energised electrical services, adjacent to a road or traffic corridor, or in or near a confined space such as a tank (s291), so a SWMS is mandatory under s299. The defining hazard is respirable crystalline silica: blasting concrete, masonry, stone, or any substrate containing at least 1% crystalline silica — and blasting with a silica-bearing media — is processing a crystalline silica substance, and where high risk it requires a silica risk control plan, with exposure controlled against the respirable crystalline silica workplace exposure standard of 0.05 mg/m³ (8-hour TWA). Because the blasting is in the open, the dust does not stay with the blaster: it drifts, so the duty of care extends to other workers and the public exposed downwind. Old coatings add a lead and heavy-metal exposure, the high-pressure abrasive stream can amputate or lacerate, and noise is extreme. The SWMS controls silica and drift, protects the public, manages height, traffic, energised services and confined-space triggers, and provides air-supplied respiratory protection. Hazardous chemicals are managed under Part 7.1 and SafeWork NSW is the regulator.

Hazards identified

7 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination — Remove the component and blast it in an enclosed, extracted facility off site so no open-air silica drift is created
2. 2Substitution — Substitute a non-silica abrasive media (garnet, steel grit) and a wet or vacuum-shrouded blasting method for dry silica-bearing media
3. 3Engineering — Containment screening, shrouds and vacuum-recovery to capture dust at source and prevent drift
4. 4Engineering — Silica risk control plan with real-time dust monitoring and exposure verification against 0.05 mg/m³
5. 5Engineering — Edge protection and platforms for height, traffic management for road proximity, and isolation of energised services
6. 6Administrative — Exclusion zone downwind sized to the drift, with public and other-worker protection and wind stop-criteria
7. 7Administrative — Health monitoring for silica and, where old coatings are blasted, for lead; with a confined-space permit where a tank is entered
8. 8Administrative — Lead-risk controls — containment, hygiene facilities and decontamination — where coatings contain lead
9. 9PPE — Air-supplied (Type CE) blasting helmet and respirator, not a filter mask, for the blaster
10. 10PPE — Blast-resistant clothing, gloves, hearing protection and eye protection for the blaster and attendants

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

At 7:00 am a blasting crew from Ironclad Surface Prep arrives to strip an old bridge handrail beside a suburban road. Two field triggers are obvious before they start: the work is at height over a footpath, and dust will drift toward houses downwind. The leading hand sets a containment screen and a vacuum-recovery shroud on the nozzle to capture dust at source, marks a downwind exclusion zone, and sets a wind stop-criterion — if the breeze swings toward the school across the road, blasting stops. A traffic plan closes the adjacent lane and edge protection is rigged on the elevated work platform. Because the handrail's old paint tests positive for lead, lead-risk controls and hygiene facilities are set and both lead and silica health monitoring are on the crew's program. The blaster works in an air-supplied blasting helmet — never a filter mask — with a dust monitor running to verify exposure stays under 0.05 mg/m³. Mid-morning the wind shifts; blasting stops until it settles. Spent abrasive and lead-laden residue are contained and removed as controlled waste rather than washed to the gutter.

Related legislation

• WHS Act 2011 (model)
• WHS Regulation 2025
• Abrasive Blasting Code of Practice
• Managing Risks of Hazardous Chemicals in the Workplace Code of Practice