Demolition is among the highest-risk activities for respirable crystalline silica (RCS) exposure in Australia — RCS is one of the most dangerous dust and airborne contaminants regulated under Australian workplace exposure standards. Unlike manufacturing or mining—where processes are standardised and controls can be engineered into the work—demolition presents a uniquely challenging environment: multiple hazardous materials co-existing on a single site, rapid and unpredictable work sequences, diverse trades working simultaneously, and often uncontrolled or partially controlled conditions.
This article is your practical guide to dust monitoring for demolition and remediation projects. We cover the regulatory requirements, the phases of monitoring, the controls that work on demolition sites, and the record-keeping obligations that apply.
Why Demolition Is Uniquely Challenging for Dust Management
Demolition work combines several factors that make dust control and monitoring more complex than in other industries:
Multiple hazardous materials. A single building may contain RCS-bearing materials (concrete, brick, mortar, clay tiles), asbestos-containing materials (cement sheets, insulation, floor tiles), and inert dusts. Older fibre cement products are particularly problematic because they may contain both silica and asbestos, requiring parallel management strategies.
Uncontrolled work environment. Demolition is inherently destructive. Controls that work in a quarry or stone fabrication facility—fixed enclosures, ventilation systems, tool suppression—are not always practical on a demolition site. You’re often working outdoors or in buildings with numerous access points and changing layouts.
Rapid pace and task variability. One hour your team is breaking concrete with a jackhammer; the next, they’re stripping cladding by hand, or loading debris into a bin. Task hazards change constantly, so generic control measures often fail to address the real exposure drivers.
Multiple trades on site. Electricians, plumbers, asbestos removalists, and general demolition crews may all be working simultaneously, with varying levels of awareness about dust hazards and PPE requirements.
Workers unfamiliar with the site. Demolition teams move from site to site. Unlike permanent workforces, they may not be familiar with the specific hazards, control arrangements, or even the layout of a particular building.
These factors make proactive monitoring and control critical. You cannot assume that “generic” demolition practices will keep exposures below the WES; you must measure, assess, and adjust.
The Silica Hazard in Demolition: Which Materials Carry the Highest Risk
Not all demolition dust is created equal. Understanding which materials present the greatest RCS risk helps you prioritise monitoring and control efforts.
High-Risk Materials for RCS
Concrete (all types) contains crystalline silica. Any task that breaks, cuts, or grinds concrete generates RCS-bearing dust. The risk is particularly high for:
– Jackhammer work on concrete slabs and walls
– Concrete cutting and sawing
– Grinding concrete for levelling or cleaning
– Demolition of concrete beams and structural elements
Brick and masonry contain quartz and are a significant RCS source, especially when:
– Bricks are broken by hand or machine
– Mortar is chiseled or ground away
– Old clay bricks are crushed during selective demolition
Mortar between bricks is often high in silica content, especially in older buildings. Grinding or chiseling mortar joints creates substantial RCS exposure risk.
Clay tiles (roof and floor) contain crystalline silica and generate high dust concentrations when broken or cut.
Compressed fibre cement sheets (common in older Australian buildings for fencing, cladding, and lining) present a dual hazard: they may contain both asbestos and silica. Even if asbestos testing is negative, these products often contain 20–40% silica.
Medium-Risk Materials
Stone and aggregate (granite, sandstone, limestone) contribute to RCS exposure depending on the percentage of quartz and the task intensity.
Renders and plasters often contain silica (especially sand-based renders), though the exposure is typically lower than concrete or brick.
Lower-Risk Materials (but not risk-free)
General rubble and inert waste may contain some RCS-bearing fragments but present lower exposure than the materials listed above, provided controls are in place.
The density and specificity of RCS in the material—combined with the destructiveness of the task—determines the monitoring and control intensity you’ll need.
Demolition Tasks and Their Silica Exposure Risk
The table below ranks common demolition tasks by their typical RCS exposure risk. This helps you identify where monitoring should focus and which tasks require the most aggressive controls.
| Task | Primary Material | Exposure Risk | Typical Exposure Profile |
|---|---|---|---|
| Jackhammer work on concrete | Concrete | HIGH | 0.1–0.5+ mg/m³ RCS (often exceeds WES) |
| Concrete sawing/cutting | Concrete | HIGH | 0.05–0.2+ mg/m³ RCS |
| Brick removal by hand | Brick/mortar | MEDIUM–HIGH | 0.03–0.15 mg/m³ RCS |
| Mechanical brick removal | Brick/mortar | HIGH | 0.1–0.3+ mg/m³ RCS |
| Tile breaking | Tiles | MEDIUM–HIGH | 0.05–0.2 mg/m³ RCS |
| Concrete grinding/polishing | Concrete | HIGH | 0.1–0.4+ mg/m³ RCS |
| Fibre cement sheet cutting/breaking | Fibre cement | MEDIUM | 0.03–0.1 mg/m³ RCS or silica + asbestos |
| Rubble crushing/screening | Mixed materials | MEDIUM | 0.02–0.1 mg/m³ RCS |
| Sorting and loading debris | Mixed materials | LOW–MEDIUM | 0.01–0.05 mg/m³ RCS |
| Sweeping and housekeeping | Settled dust | LOW–MEDIUM | 0.01–0.05 mg/m³ RCS |
Note: These ranges are indicative only. Actual exposures depend on duration, intensity, control effectiveness, worker proximity, and environmental factors.
Demolition-Specific Regulatory Requirements
In Australia, demolition work is governed by:
Work Health and Safety Act 2011 (federal) and state equivalents, which impose duties on PCBUs (persons conducting a business or undertaking—typically employers and contractors) to ensure, so far as reasonably practicable, the health and safety of workers.
Work Health and Safety Regulations 2011 (federal) and state equivalents, which specify:
– Hazard identification and risk assessment (Section 36)
– Implementation of controls in accordance with the hierarchy of controls (Section 36)
– Health monitoring when there is a risk of exposure above the WES (Section 247 in some jurisdictions)
– Record-keeping of monitoring data (30 years for RCS)
Safe Work Australia Model Code of Practice: Hazardous Chemicals—Crystalline Silica (November 2025) provides guidance on:
– Identifying work involving crystalline silica
– Assessing and controlling silica exposure
– Air monitoring and health monitoring
– Record-keeping
State-based requirements may vary (NSW, Victoria, Queensland, WA, etc.). Some states have additional specific demolition codes of practice or guidance documents. Always check your state regulator’s website.
The Dual Hazard: Silica and Asbestos
If your demolition project is in a building constructed before the 1980s (or later, depending on the material type), asbestos is almost certainly present. When both silica and asbestos are present:
- You must manage both hazards simultaneously
- Asbestos removal often triggers different work procedures and licensing requirements (depending on the state and quantity)
- In some cases, asbestos is removed before general demolition begins; in others, selective separation occurs during demolition
- This article focuses on silica monitoring; consult your state regulator and licensed asbestos assessor for asbestos-specific requirements
For demolition projects, best practice is to engage both an asbestos specialist and an occupational hygienist (or a multi-disciplinary team) to ensure all hazards are identified and managed.
Three Phases of Demolition Monitoring
Effective monitoring spans the entire demolition lifecycle:
Phase 1: Pre-Demolition Hazard Identification and Risk Assessment
Before any work begins, engage a qualified occupational hygienist for silica and dust monitoring (preferably AIOH-certified) to:
- Conduct a materials survey. Identify all materials that contain or may contain RCS or asbestos. This typically includes:
- Visual inspection of the building
- Historical research (building age, construction type, material records if available)
- Sampling of suspect materials (sent to an accredited lab)
-
A written report detailing hazardous materials and their locations
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Develop a demolition-specific risk assessment that identifies:
- All tasks that will generate dust containing RCS
- Duration and intensity of each task
- Who will be exposed (directly and nearby)
- Which materials present the greatest risk
-
Preliminary control strategy
-
Establish a baseline monitoring plan. This outlines:
- Which tasks require personal monitoring
- Where static monitors will be placed (site boundary, adjacent properties, disposal areas)
- Monitoring frequency (during high-risk tasks, at least daily)
- Who will conduct the monitoring (internal staff or external contractor)
Phase 2: Monitoring During Demolition
During active demolition, conduct:
Personal monitoring for workers performing high-risk tasks:
– Passive gravimetric sampling (8-hour TWA) on workers performing jackhammer work, concrete sawing, brick removal, tile breaking
– Frequency: at least once per week for each task type, or daily if preliminary results approach the WES
– Real-time monitoring (dust meters) to detect exceedances and allow immediate intervention
Static (area) monitoring at site boundaries:
– Monitor dust concentrations at property boundaries to ensure dust is not migrating off-site
– Place monitors upwind and downwind of demolition activity
– Frequency: daily, or continuously if real-time monitors are deployed
Task-specific observations:
– Document control effectiveness (is wet suppression working? Is the dust enclosure sealed? Is RPE being worn correctly?)
– Adjust controls if real-time data shows concentrations approaching the WES
Phase 3: Post-Demolition Clearance and Confirmation
After demolition is complete:
-
Conduct a site clearance inspection. This is a visual and (if needed) air monitoring assessment to confirm that demolition dust is no longer being generated and that residual contamination is minimal.
-
Final monitoring (if required):
- Background dust monitoring to establish that site dust levels have returned to baseline
- Confirmation that waste has been appropriately disposed of
Pre-Demolition Dust Risk Assessment: What It Includes
A demolition-specific dust risk assessment is the foundation of your monitoring and control program. Here’s what it must cover:
1. Scope and hazard identification
– All materials containing RCS or suspected RCS
– All work tasks that will generate dust
– Occupational groups (workers, site managers, visitors, nearby residents)
– Intensity and duration of exposure (full-shift, intermittent, peak exposures)
2. Exposure scenarios
– High-risk scenarios (e.g., 8-hour continuous jackhammer use)
– Typical scenarios (e.g., 2-hour concrete sawing with breaks)
– Low-risk scenarios (e.g., rubble loading into bins)
3. Control strategy
– Elimination and substitution opportunities (can the task be done differently to avoid RCS?)
– Engineering controls (water suppression, enclosure, on-tool extraction)
– Administrative controls (work sequencing, rotation)
– PPE (respiratory protection, eye protection, skin protection)
4. Monitoring plan
– Which tasks require personal air monitoring
– Where static monitors will be placed
– Monitoring frequency and timing
– Trigger levels for intervention (if real-time data shows 50% of the WES, increase controls)
5. Health and safety plan
– Induction for workers (hazards, controls, PPE, reporting)
– Coordination with asbestos work (if applicable)
– Emergency procedures (dust exceedance, health incident)
– Worker rights (right to refuse unsafe work, right to request health monitoring)
6. Record-keeping
– How monitoring data will be collected, stored, and retained (30 years)
– Who is responsible for records
– How workers will access their monitoring results
Monitoring During Demolition: Personal and Static Monitoring
Personal Monitoring for Task-Specific Exposures
Objective: Measure the inhalable and respirable dust exposure of workers performing high-risk tasks.
Method: Passive gravimetric sampling (pump-based, usually 25 mm filter cassette, respirable size fraction) worn on the worker’s breathing zone.
Frequency: At minimum, once per week for each high-risk task. If preliminary results are above 50% of the WES (0.025 mg/m³), increase frequency to every shift or every 2–3 days until you confirm that controls are effective.
Duration: 8-hour full-shift samples for workers whose entire shift involves the task, or task-specific samples (2–4 hours) if the task is intermittent.
Analysis: Samples are sent to an accredited laboratory (NATA-certified) for analysis. Results are reported as RCS concentration (mg/m³) in the respirable fraction.
Action: If a sample exceeds the WES (0.05 mg/m³), immediately:
1. Stop or modify the task
2. Review and upgrade controls
3. Re-monitor after controls are upgraded
Static (Area) Monitoring
Objective: Monitor dust concentrations at the site boundary and in areas where public access is possible, to ensure dust is not migrating off-site and to detect changes in task intensity or control effectiveness.
Method: Real-time dust monitors (e.g., light-scattering instruments) placed at strategic locations around the site, ideally on site plans showing property boundaries.
Placement:
– Upwind and downwind of the primary demolition area (to assess dispersion)
– At any point of potential off-site drift (downwind neighbours, public footpaths)
– Near loading and waste areas
– One background monitor away from the site (to establish baseline)
Frequency: Continuous during demolition, or at least daily during high-risk phases.
Threshold: If area monitoring shows concentrations approaching the WES or rising sharply, increase controls (water suppression, reduce task intensity, extend monitoring frequency).
Real-Time vs Gravimetric Monitoring
Real-time monitors (dust meters) provide instant feedback but are less precise than gravimetric sampling. Use them to:
– Detect when a task is generating excessive dust
– Trigger immediate control adjustments
– Identify areas of high dust concentration
Gravimetric sampling (lab-based) is more accurate and provides the definitive record for compliance. It requires a few days for results but is the only method that meets regulatory requirements for demonstrating compliance with the WES.
Best practice: Combine both. Use real-time monitors for on-site decision-making; use gravimetric sampling for the official compliance record. For a detailed comparison, see our guide on real-time silica monitoring vs gravimetric sampling to determine what is right for your site.
Choosing Controls for Demolition: The Hierarchy of Controls
The WHS Act and Safe Work Australia guidance require controls to be implemented in order of preference, from most effective to least:
1. Elimination and Substitution
Can you avoid the RCS hazard altogether?
– Use non-destructive deconstruction (careful removal of materials for reuse or recycling) instead of demolition?
– Use less destructive methods (hand tools, shears, saws with extraction) instead of jackhammers?
– Hire a specialist contractor with proven low-dust methods?
Elimination is always preferred and should be explored first.
2. Engineering Controls
Wet suppression (water spray):
– Most effective for concrete and masonry work
– Equipment: water sprays on demolition equipment, hand-held spray rigs, mist cannons
– Timing: apply water continuously to the point of work
– Limitations: may not be practical in winter or with electrical hazards; requires dust extraction in combination for maximum effect
– Cost: moderate; equipment hire plus water supply
Dust enclosure:
– Partial or full enclosures around the work area, with water suppression and dust extraction
– Most effective for concrete cutting, grinding, and small-scale brick work
– Limitations: reduces worker mobility; not practical for large-scale demolition
– Cost: moderate to high
On-tool dust extraction:
– Wet or dry extraction attached directly to the demolition tool (jackhammer, grinder, saw)
– Effectiveness: moderate; depends on tool design and seal
– Limitations: requires trained operation; maintenance-sensitive
– Cost: moderate; includes equipment, filters, disposal
Ventilation and extraction:
– Local exhaust ventilation (LEV) systems for fixed work areas
– General ventilation to reduce background dust
– Limitations: difficult to implement effectively on dynamic demolition sites
– Cost: high
3. Administrative Controls
Work sequencing and rotation:
– Schedule high-risk tasks during low-wind conditions
– Rotate workers away from continuous exposure to the same task
– Limit the duration of high-intensity work (e.g., 2 hours of jackhammer work followed by a break in a low-dust area)
Work procedures:
– Briefings and toolbox talks on dust hazards
– Correct use of controls and PPE
– Regular monitoring of control effectiveness
– Stop-work procedures if exposures approach the WES
4. Personal Protective Equipment (PPE)
Respiratory protective equipment (RPE):
– Class P3 (or equivalent) filter cartridges for respirable dust
– Half-mask or full-face respirator, fitted to the wearer
– RPE is NOT a substitute for engineering controls; it is used when engineering controls cannot fully prevent exposure
– Limitations: discomfort, poor compliance, fit issues, heat stress in hot weather
– Cost: low per worker per day
Eye and skin protection:
– Safety glasses to prevent dust irritation
– Long-sleeved clothing, gloves
Typical Control Combination for Demolition
High-risk tasks (jackhammer, concrete sawing):
– Water suppression (primary control) + dust extraction
– On-tool extraction or local enclosure
– RPE (P3 filter) for workers and nearby workers
– Real-time monitoring to track effectiveness
Medium-risk tasks (brick removal, grinding):
– Water suppression or wet methods
– Site wetting to suppress background dust
– RPE for primary workers
– Gravimetric monitoring weekly
Lower-risk tasks (rubble loading, sweeping):
– Site wetting
– RPE if dust is visibly high
– Gravimetric monitoring as baseline
Record-Keeping for Demolition Projects
Australian law (Safe Work Australia Model Regulations, state WHS Regulations) requires you to keep records of air monitoring for RCS for at least 30 years. This applies to demolition as much as any other industry.
Records to maintain:
- Pre-demolition hazard assessment and risk assessment (site report, materials survey, control plan)
- Monitoring data:
- Sample ID, date, time, worker/area, task performed
- Sampling method (personal/static, duration, equipment)
- Lab analysis results (RCS concentration, analytical method, lab name and NATA accreditation)
- Real-time monitor logs (if used)
- Control measures implemented (photos, descriptions, dates of upgrade/changes)
- Worker exposure records (which workers were sampled, which tasks, exposure levels)
- Health monitoring records (if triggered: baseline health assessment, follow-up assessments, GP reports)
- Corrective actions (if WES exceeded: what was done, when, follow-up monitoring)
- Training and induction records (worker hazard awareness, control procedures)
Storage and access:
– Records must be kept on-site (or readily accessible) during the demolition
– After completion, store securely with controlled access (usually with the PCBU’s main occupational health and safety coordinator)
– Provide workers with access to their own monitoring results within a reasonable timeframe (typically 2–4 weeks after lab analysis)
Frequently Asked Questions
Q: Is demolition work automatically classified as high-risk for silica exposure?
A: Demolition is presumed to involve significant silica exposure risk, especially if concrete, brick, mortar, or masonry materials are present. You do not need to assume lower exposure; standard practice is to implement controls and conduct monitoring from the start. If you perform a detailed risk assessment and can demonstrate that exposure is likely to remain below the WES (e.g., small-scale careful deconstruction with water suppression), you may reduce monitoring intensity, but this requires evidence and a documented assessment.
Q: Can we use health monitoring instead of air monitoring for demolition projects?
A: No. Health monitoring (chest X-rays, lung function tests) is a complement to air monitoring, not a replacement. Air monitoring is required to demonstrate that controls are working and that the WES is not being exceeded. Health monitoring tells you whether workers’ health is being affected after the fact. You must do both: air monitoring to prevent overexposure, and health monitoring to detect early disease in exposed workers.
Q: What should we do if a personal air sample shows the worker exceeded the WES during one shift?
A: This is a priority situation. Immediately (on the same day or next day):
1. Stop or significantly modify the task that caused the exceedance
2. Implement additional controls (e.g., water suppression, RPE upgrade, tool extraction)
3. Brief the worker on what happened and what changes you’re making
4. Notify the site manager and project supervisor
5. Re-monitor the same task within 1–2 days (after controls are upgraded) to verify the exceedance has been corrected
6. Document the exceedance and corrective action in your records
7. Consider whether the worker should be offered health monitoring (this may be required under your state’s WHS Regulations if there has been a significant overexposure)
Q: How often should we monitor if we’re doing multiple demolition projects?
A: Frequency depends on task risk and control effectiveness. Standard practice is:
– Weekly personal monitoring for high-risk tasks (jackhammer, concrete sawing)
– Fortnightly if preliminary data shows exposures well below 50% of the WES
– Daily if exposures are approaching the WES or if controls are new/unproven
– Static monitoring should occur daily during active work; real-time monitors can provide continuous data
Q: Can we use the same control setup on every demolition site?
A: Not entirely. While a basic control hierarchy (water suppression + dust extraction + RPE) is standard, each site presents different challenges: building materials, site layout, weather conditions, access for equipment, and nearby sensitive receivers (schools, hospitals, residences). Always conduct a site-specific risk assessment and adjust controls accordingly. What works on a rural greenfield demolition may not work in a dense urban environment.
Q: Who is responsible for monitoring—the main contractor or the demolition subcontractor?
A: The PCBU (the business or organisation conducting the work) is responsible. In most demolition projects, that’s the main contractor or project manager. However, they may engage a demolition specialist contractor to perform the work. Both parties have duties: the PCBU must ensure that monitoring is conducted; the specialist contractor must cooperate and provide access for monitors. The responsibility for conducting the actual sampling (engaging the hygienist, coordinating lab analysis) is typically delegated to the demolition subcontractor, but overall accountability sits with the PCBU.
Q: What’s the difference between a pre-demolition assessment and an ongoing risk assessment?
A: The pre-demolition assessment is a one-time assessment before work begins. It identifies all hazards, surveys materials, and establishes the monitoring and control plan. The ongoing risk assessment is a continuous process: as you work, you gather monitoring data, observe control effectiveness, and make adjustments. If monitoring shows that exposures are higher than expected, or if a different material is discovered, you update your controls and risk assessment. Both are required.
Summary and Next Steps
Demolition presents unique dust and silica exposure challenges. Success requires:
- Early engagement of an occupational hygienist for pre-demolition assessment and materials survey
- Robust controls from the start (water suppression, dust extraction, engineering measures)
- Regular monitoring (personal and static) throughout the project
- Responsive management (adjust controls if monitoring shows high exposures)
- Comprehensive record-keeping (30-year retention for regulatory compliance and worker protection)
If you’re managing or performing a demolition project and are unsure whether you have the right monitoring and control program in place, get professional advice early. The cost of a pre-demolition assessment is far less than the cost of a WHS enforcement action or a worker developing silica-related disease.
Anitech Group provides pre-demolition assessments, monitoring coordination, and corrective action planning for demolition projects across Australia. We work with general contractors, demolition specialists, and project managers to ensure compliance and worker protection. Get a pre-demolition dust risk assessment and monitoring program—fast turnaround for project timelines.
IMAGE_REQUIREMENTS
- FEATURE: 1200x630px. Overhead view of a demolition site with a jackhammer operator at work, a water suppression mist visible, dust monitors positioned at the perimeter, and a safety officer in the foreground reviewing a monitoring report.
- BODY_1: 800x450px. Close-up of concrete being broken by a jackhammer with visible dust clouds and water suppression spray; after “Demolition Tasks and Their Silica Exposure Risk” heading.
- BODY_2: 800x450px. Pre-demolition survey scene: hygienist with clipboard inspecting concrete slab, with visual callouts showing sampling locations and hazard markers; after “Pre-Demolition Dust Risk Assessment” heading.
