Abrasive Blasting

Silica sand is banned in Australia. The substrate may be more dangerous than the abrasive (lead paint, asbestos coatings, RCS in concrete). Air-supplied respirator + enclosed booth where reasonably practicable.

Quick Take

• Silica sand is prohibited as an abrasive media (>1% free crystalline silica).
• Air-supplied respirator AS/NZS 1716 Class CE, mandatory for blasters and pot attendants in any open / unventilated work.
• Dead-man control on the nozzle — releases pressure if dropped.
• Substrate sampling before blasting any old surface (lead, asbestos, PCB).
• Health monitoring mandatory for ongoing silica / lead exposure (Reg 368).

1. Process types

Method	Notes
Dry pneumatic	Air propels abrasive; highest dust risk.
Wet	Abrasive + water near nozzle for dust suppression; chromate/nitrate inhibitors restricted.
Cabinet	Enclosed; operator at viewing window; usually no RPE if maintained.
Blast room / chamber	Operator inside, hood/helmet airline respirator.
Vacuum	Shroud + seal + vacuum debris removal; only effective with seal intact.
Centrifugal wheel	Inside an enclosure; lowest operator exposure.
Emerging	Sodium bicarbonate, sponge, dry-ice (CO₂).

2. Prohibited media

Media	Status
Silica sand (>1% free crystalline silica), incl. beach/river/pool-filter sand	Banned in Australia
Arsenic	>0.1% prohibited
Beryllium	>0.1% prohibited
Cadmium	>0.1% prohibited
Lead	>0.1% (or operator exposure > WHS limit) prohibited
Antimony, cobalt, nickel, tin	>0.1% each prohibited
Chromium	>0.5% restricted in dry; chromate/nitrate/nitrite restricted in wet
Radioactive	>1 Bq/g prohibited

3. Acceptable abrasives

• Steel grit / shot, chilled iron grit (recyclable, low shatter).
• Garnet (verify low silica), aluminium oxide.
• Crushed glass, glass beads, plastic beads, sodium bicarbonate.
• Metal slag — verify content with supplier's analysis certificate.
• Dry ice.

Recycled abrasive must be verified before reuse — toxics (lead) and respirable silica concentrate during recycling.

4. Substrate hazards (often the bigger risk)

Substrate	Hazard
Lead paint (>1% by dry weight)	Reg 392 lead-process; mandatory health monitoring. Blood-lead thresholds: 5 µg/dL reproductive females, 20 µg/dL others.
Concrete, sandstone, brick	RCS dust → silicosis.
Asbestos coatings (textured paint, vinyl tile, fibre-cement, plaster)	Sample + NATA analysis before blasting. High-pressure water/air on ACM is prohibited.
PCB-coated surfaces	Prohibited as wet additive; specific decontamination required.

5. Engineering controls — order

![[abrasive_blasting_img001.jpg|520]] Figure 1 — Cabinet blasting: fully enclosed, operator outside at viewing window. The cleanest workflow for small parts.

![[abrasive_blasting_img002.jpg|520]] Figure 2 — Blast room/chamber: operator inside wearing hood/helmet airline respirator (170 L/min continuous, AS/NZS 1716 Class CE). Mechanical exhaust runs ≥ 5 min after blasting before unmasking.

1. Eliminate: chemical stripper, heat gun, power tools with dust collection, manual sand.
2. Isolate: cabinet → blast room → temporary enclosure → vacuum blasting.
3. Engineer: mechanical exhaust 0.3–0.4 m/s air velocity; recirculation + filtration; cyclones; airwashes.
4. Admin: exclusion zones (extended downwind), schedule outside normal hours, cease in wind, wet vacuum / HEPA housekeeping.
5. PPE (always required for blasters): air-supplied hood/helmet AS/NZS 1716 Class CE.

6. Open-air work — exclusion zones

![[abrasive_blasting_img003.jpg|520]] Figure 3 — Exclusion zone for open-air blasting. Buffer extends downwind; signed; barricaded; no unauthorised entry. Size determined by risk assessment + wind.

• Signage: "Abrasive blasting in progress — authorised only — RPE required".
• Cease blasting in wind (compromises exclusion zone).
• Tear-resistant screens (polypropylene; not porous cloth) for temporary enclosures.
• 2 m vertical extension on enclosure tops.

7. Dead-man control & whip

![[abrasive_blasting_img004.jpg|520]] Figure 4 — Nozzle dead-man control: releases air pressure when the operator's hand is removed. Mandatory; pneumatic for hose < 40 m, electric for > 40 m.

• Anti-static hose with earth wire.
• Hose whip-checks at every coupling.
• Coupling safety locks.
• Hose straight or coiled when not in use.

8. Air-supplied respirator (mandatory)

• AS/NZS 1716 Class CE — air-supplied hood/helmet, positive pressure, 170 L/min continuous at the regulator (more if cooling suit).
• Inner bib, hi-vis cape.
• AS/NZS 1715 breathing-air quality (dry, oil-free, CO alarm).
• Individually fitted; disinfected if shared.
• Headbands, valves, face piece checked before each use.
• Pot attendant: air-purifying respirator backup during maintenance / shutdown.

9. Noise

• Nozzle discharge: 112–119 dB(A) typical; peak to 145 dB(C) at "abrasive runs out".
• Cabinet operators: 90–101 dB(A) — only ~12 min unprotected per 8-h shift to stay under 85 dB(A) Aeq.
• Sound-absorbent enclosures, mufflers, silencers + HPDs + audiometric testing.
• See [[managing_noise_and_preventing_hearing_loss]].

10. Health monitoring (Reg 368)

Mandatory for ongoing exposure to silica, lead, asbestos, cadmium, arsenic, chromium, cobalt:

• Biological monitoring (blood lead, urine chromium etc.).
• Chest X-ray, spirometry for silica.
• 30-year record retention (40 for asbestos).
• Worker informed pre-engagement; medical practitioner supervision.

11. Records & training

• Air-monitoring results — 30 yrs.
• Plant inspection logbook — daily operator + competent-person periodic.
• Health-monitoring reports — confidential, 30 yrs (40 asbestos).
• Substrate-test results, NATA analysis (where applicable).
• Training: PPE use/maintenance/storage, hazard recognition, emergency procedures, first aid.

12. Common pitfalls / quick wins

Do

• Verify abrasive certificate before purchase — written silica % from supplier.
• Sample old paint and old surfaces before any blasting.
• Maintain the vacuum-blast seal; train operators not to lift the nozzle off the surface.
• Run baseline blood-lead before any lead-paint work; periodic during.
• Run audiometric testing for cabinet operators; noise is often missed.
• Verify cabinet maintenance (door seals, viewing window, exhaust filter) before "no PPE" assumption.

Don't

• Use silica sand. Banned, full stop.
• Skip air monitoring "because we always blast garnet" — different hose, different substrate, different result.
• Let pot attendants near a depressurised pot without RPE.
• Recycle abrasive without cleaning verification.
• Blast asbestos coatings with air or high-pressure water.

13. Cross-references

• See also: [[welding_processes]], [[spray_painting_and_powder_coating]]
• RCS detail: [[respirable_crystalline_silica]] (Phase 4, §07)
• Asbestos: [[manage_and_control_asbestos]] / [[safely_remove_asbestos]] (Phase 4)
• Noise: [[managing_noise_and_preventing_hearing_loss]]
• Glossary: [[glossary_and_key_concepts]]

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Source: model_code_of_practice_abrasive_blasting.pdf (Safe Work Australia, model Code of Practice, CC-BY-NC 4.0). Edition: August 2021 (carries Jul 2020 GHS Rev 7 amendment; supersedes May 2018). Last verified against SWA: 2026-04-28.