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Silica dust controls on residential construction sites

Engineered stone banned July 2024. WES for respirable crystalline silica is 0.05 mg/m3 (8-hr TWA). Controls hierarchy, SWMS, RPE selection, and health monitoring.

By Dan Waring. Last updated 10 May 2026. Verified 10 May 2026.

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TL;DR

Respirable crystalline silica (RCS) is present in concrete, brick, fibre cement, sandstone, and most masonry on a residential site. The workplace exposure standard (WES) is 0.05 mg/m³ as an 8-hour TWA (half the old standard). Engineered stone is banned outright from 1 July 2024. From 1 September 2024, any material with at least 1% crystalline silica is a regulated crystalline silica substance (CSS): dry-cutting without controls is not compliant. The hierarchy runs water suppression and on-tool extraction first, RPE (P2 minimum, fit-tested) last. High-risk processing in construction requires a silica risk control plan or a SWMS covering controls. Workers with significant exposure need health monitoring.

When you need to act

Any task that cuts, grinds, drills, sands, or crushes a silica-containing material generates RCS. Prolonged uncontrolled exposure causes silicosis, an incurable lung disease. On a standard residential build, high-risk tasks include:

  • Cutting or drilling fibre cement sheet (Villaboard, HardieFlex, compressed sheet)
  • Angle-grinding, saw-cutting, or core-drilling concrete slabs and columns
  • Cutting, grinding, or pointing brickwork or blockwork
  • Dry-cutting roof tiles or pavers
  • Sanding or mixing sand-based render and mortar
  • Demolition of concrete, brick, or masonry elements

Common building materials by approximate silica content:

MaterialCrystalline silica content
SandstoneUp to 90%
Brick (clay)25-50%
Concrete and mortar25-50%
Fibre cement sheet15-30%
Roof tiles (clay/concrete)15-40%
Sand/cement render30-50%
Engineered stone (now banned)Up to 93%

Any material with at least 1% crystalline silica by weight is a crystalline silica substance (CSS) under the amended WHS Regulations (effective 1 September 2024, verified 2026-05-10).

The engineered stone ban

From 1 July 2024, it is an offence for a PCBU to carry out, or direct or allow a worker to carry out, work involving the manufacture, supply, processing, or installation of engineered stone benchtops, panels, or slabs (Safe Work Australia, Engineered stone ban, verified 2026-05-10).

This covers new supply and installation. Removal of legacy engineered stone already installed (for repair or renovation) may be permitted under jurisdiction-specific exemptions: check your state WHS regulator for current exemption details before touching any existing engineered stone. Exemptions require a WHS regulator determination that the standard of health and safety will be equivalent to or better than not granting it.

Regulatory framework (from 1 September 2024)

The Work Health and Safety Amendment (Crystalline Silica Substances) Regulation 2024 (adopted in NSW and all harmonised jurisdictions, verified 2026-05-10) inserts Chapter 8A into the WHS Regulations. Key obligations:

  1. Assess all CSS processing for whether it is high risk.
  2. Apply a silica risk control plan (or SWMS in construction) for any high-risk processing before work starts.
  3. Air monitoring: if results exceed the WES, notify the WHS regulator within 14 days of receiving the report.
  4. Health monitoring for workers with significant exposure to RCS.
  5. Silica Worker Register (NSW): from 1 October 2025, notify SafeWork NSW within 28 days of a worker commencing high-risk silica processing work (SafeWork NSW, Silica Worker Register, verified 2026-05-10).

The WES for RCS remains 0.05 mg/m³ as an 8-hour TWA (Safe Work Australia, WES for RCS, verified 2026-05-10). From 1 December 2026, the WES will be relabelled a Workplace Exposure Limit (WEL), with a “keep exposure as low as reasonably practicable” obligation added on top of the numerical limit (Safe Work Australia, WEL from 1 December 2026, verified 2026-05-10).

Controls hierarchy

Apply controls in order. Move to the next level only when the one above is not reasonably practicable.

1. Elimination

  • Specify products with no or minimal crystalline silica content where technically acceptable.
  • Use pre-cut materials to avoid cutting on site (e.g., pre-cut fibre cement to dimension).
  • Design out the need to drill or grind in place (e.g., adjust framing to avoid core-drilling slabs).

2. Substitution and isolation

  • Replace silica-heavy materials with lower-silica alternatives where the application allows.
  • Enclose dusty processes in a screened or hoarded area, away from other workers.
  • Use automated or remote-controlled equipment where cutting or grinding would otherwise be manual.

3. Engineering controls

These are the primary practical controls on residential construction sites:

Water suppression (wet cutting)

  • Attach a water feed directly to the blade or bit at the point of cut. Continuous water flow suppresses RCS before it becomes airborne.
  • Score-and-snap is preferred over cutting for fibre cement: no blade, no dust, no suppression required.
  • Manage slurry: wet cleanup by mopping or hosing at low pressure. Never use compressed air to blow dust or slurry dry.

On-tool dust extraction

  • Fit angle grinders, circular saws, and hammer drills with on-tool dust extraction shrouds connected to a HEPA-filtered vacuum (class H vacuum for silica duty).
  • On-tool extraction is a form of local exhaust ventilation (LEV): it captures RCS at the point of generation before it disperses.
  • Check extraction shroud fit and vacuum filter condition before each shift.

Local exhaust ventilation (LEV)

  • For fixed cutting stations (tile saws, bench-mounted grinders), use a fixed LEV hood capturing dust directly at the source.
  • LEV must be sized and positioned to capture dust before it reaches the breathing zone.

4. Administrative controls

  • Rotate workers to limit individual exposure duration on high-dust tasks.
  • Wet-clean work areas at the end of each shift. Never dry sweep or use compressed air.
  • Restrict access to dusty work areas to workers with controls in place.
  • Maintain a register of workers exposed to RCS and hours of high-dust work.

5. Respiratory protective equipment (RPE): last resort only

RPE does not eliminate the hazard: it is the last line of defence after higher-order controls have been applied (WorkSafe VIC, Preventing exposure to crystalline silica dust, verified 2026-05-10).

Selection per AS/NZS 1715:2009 Selection, use and maintenance of respiratory protective equipment (verified 2026-05-10):

TaskMinimum RPE
Incidental exposure, short-duration (score-and-snap, one-off hole)P2 disposable half-facepiece (fit-tested)
Sustained cutting or grinding (repeated or prolonged)P2 half-face respirator with replaceable cartridge (fit-tested)
High-dust sustained work or workers with facial hairPowered air-purifying respirator (PAPR): eliminates fit-test dependency
Enclosed or confined work area with sustained dustSupplied air or PAPR minimum

Fit-testing is mandatory for all tight-fitting RPE (disposable P2 masks and half-face respirators). Fit testing must be carried out before a worker is first assigned a respirator, when they change to a different make or model, and when facial features change significantly. Workers with facial hair (beard stubble) cannot achieve a proper seal with a tight-fitting facepiece: use PAPR or supplied air.

RPE must be stored clean, inspected before each use, and replaced per manufacturer schedule or when filters are damaged or spent.

Silica risk control plan

If processing a CSS is assessed as high risk, prepare a silica risk control plan before work starts. In construction, a compliant SWMS that covers the same content satisfies this requirement (SafeWork NSW, WHS Amendment Regulation 2024, verified 2026-05-10).

The plan must:

  • Identify each task involving CSS processing and the materials involved
  • Assess whether each task is high risk
  • Describe the control measures to be applied (in hierarchy order)
  • Be developed in consultation with workers (and HSRs if applicable)
  • Be available to all workers before they start the task
  • Be reviewed when controls are no longer effective or when work conditions change

Health monitoring

PCBUs must arrange health monitoring for workers who are or may be significantly exposed to RCS (Safe Work Australia, Health monitoring for crystalline silica, verified 2026-05-10). Health monitoring must be carried out by, or under the supervision of, a registered medical practitioner with experience in occupational health.

Monitoring may include: respiratory function tests (spirometry), chest X-ray or CT scan, and a structured medical questionnaire. Results are provided to the worker and the PCBU. The PCBU must keep health monitoring records for the duration of the worker’s employment plus 30 years.

Demolition of load-bearing concrete, brick, or masonry walls or columns is HRCW, requiring a SWMS regardless of any CSS obligations. Where demolition of HRCW also involves CSS, a single SWMS can satisfy both requirements. Cutting, grinding, or drilling structural concrete for new penetrations is also likely HRCW: confirm with your WHS regulator if uncertain.

State regulator contacts

StateRegulatorWebsite
NSWSafeWork NSWsafework.nsw.gov.au
VICWorkSafe Victoriaworksafe.vic.gov.au
QLDWorkplace Health and Safety QLDworksafe.qld.gov.au
WAWorkSafe WAworksafe.wa.gov.au
SASafeWork SAsafework.sa.gov.au
TASWorkSafe Tasmaniaworksafe.tas.gov.au
NTNT WorkSafeworksafe.nt.gov.au
ACTWorkSafe ACTworksafe.act.gov.au

State regulators adopted the model WHS Regulations crystalline silica amendments with effect from 1 September 2024 (confirmed verified 2026-05-10 for NSW, VIC, QLD, WA, SA).

Common failures on site

  • Dry angle-grinding brick, concrete, or fibre cement without water suppression or on-tool extraction. Most common silica offence found in SafeWork NSW inspections.
  • P2 mask without fit-test: a P2 mask that doesn’t seal provides near-zero protection. Fit-testing is mandatory, not optional.
  • Dust dispersal: blowing dust with compressed air, dry sweeping. Both re-suspend settled RCS and extend exposure.
  • No SWMS for high-risk tasks: assuming the general site induction covers CSS. A SWMS or silica risk control plan is a separate document requirement.
  • Forgetting subcontractors: the principal contractor’s WHS duties extend to subcontractors’ workers on site. If a subcontractor is dry-cutting brick without controls, that is the principal contractor’s compliance exposure too. See WHS when engaging subcontractors.

References

See also

Last updated: 2026-05-10. Verified: 2026-05-10. Quarterly review for currency.

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