Silica in Demolition & Rehabilitation Work SWMS

Silica demolition and rehabilitation covers the demolition, breaking out and site rehabilitation of concrete, masonry, brick and stone structures, where the work both meets the definition of demolition under the model Work Health and Safety Regulations and generates respirable crystalline silica (RCS) from material that is commonly 20 to 40 per cent crystalline silica by mass. Breaking, crushing and processing structural concrete with excavators, rock-breakers, saws and crushers liberates RCS in large quantities and over sustained periods, and the demolition setting adds structural collapse, falling material and plant-interaction hazards on top of the dust. This document is deliberately comprehensive because two regimes apply together: demolition as high risk construction work, and high-risk processing of a crystalline silica substance.

Demolition involving load-bearing or structural elements is high risk construction work under the model WHS Regulations, requiring a SWMS prepared before the work commences, kept readily accessible, and given to the principal contractor if one is appointed. At the same time, breaking and processing the silica-bearing material is processing of a crystalline silica substance, which is high risk where it is reasonably likely to result in a risk to health — the practical trigger being airborne RCS above half the workplace exposure standard generated on a regular basis. The exposure standard is 0.05 mg/m3 as an eight-hour time-weighted average, which must not be exceeded, reframed as a workplace exposure limit from 1 December 2026. Where the work is high-risk silica processing, a silica risk control plan, air monitoring and health monitoring are required in addition to the demolition SWMS. This document is written on the basis that wet suppression across the demolition face is the primary silica control and that the demolition and silica controls operate together, not in isolation.

Hazards identified

10 hazards covered, sorted by priority.

Control measures

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

1. 1Elimination: where rehabilitation allows, reduce on-site breaking by removing whole elements for off-site processing, eliminating part of the silica-generating demolition.
2. 2Substitution: select lower-dust demolition methods where a choice exists — for example controlled mechanical munching with suppression over dry impact breaking.
3. 3Engineering: continuous water suppression applied across the demolition and crushing face at adequate flow as the primary silica control, keeping airborne RCS as low as reasonably practicable and below the exposure standard.
4. 4Engineering: a structural demolition sequence designed by a competent person, with exclusion zones, props or supports as required, and crushers fitted with dust suppression and guarding.
5. 5Engineering: identify and remove asbestos and other hazardous materials under the appropriate licensed regime before demolition of the affected elements begins.
6. 6Administrative: prepare a demolition SWMS before the work commences for the high risk construction work, and where breaking and processing is high-risk processing of a crystalline silica substance, prepare a silica risk control plan as well.
7. 7Administrative: arrange air monitoring to validate the silica controls hold below the exposure standard, including at the site boundary where neighbours may be affected, and notify the regulator of any exceedance within the prescribed period.
8. 8Administrative: enrol workers carrying out high-risk silica work in health monitoring supervised by a registered medical practitioner, including respiratory function testing and low-dose high-resolution chest CT, and retain records confidentially for at least 30 years.
9. 9Administrative: maintain plant-and-pedestrian exclusion zones with a spotter, control public access to the demolition area, and sequence the work to keep workers out of the dust plume and collapse zone.
10. 10PPE: a fit-tested P2 half-face respirator as the minimum residual control, upgraded to a powered air-purifying respirator for sustained breaking and crushing, selected and maintained per AS/NZS 1715 and AS/NZS 1716.
11. 11PPE: hearing protection matched to the measured noise level, eye and face protection to AS/NZS 1337.1, high-visibility clothing, gloves, and Class I or Class II safety footwear with protective toecap to AS/NZS 2210.3.
12. 12Administrative: all workers must hold a valid White Card (General Construction Induction Training, CPCCWHS1001) before entering any construction workplace.
13. 13Administrative: conduct a daily pre-start toolbox talk covering the demolition sequence, silica suppression, exclusion zones, hazardous-material status and required PPE, and record attendance in the SWMS consultation section.
14. 14Administrative: manage water and slurry runoff so silica-laden water does not enter stormwater, clean up with wet methods or an H-class vacuum rather than dry sweeping, and review and update this SWMS whenever the scope changes, after any incident, when a worker or health and safety representative raises a concern, or at minimum every 12 months.

Applicable Codes of Practice

High-Risk Construction Work triggered

Worked example

A demolition contractor is engaged to demolish a redundant reinforced-concrete pump station and rehabilitate the site. Because the work removes load-bearing concrete it is high risk construction work, so a demolition SWMS is prepared before the work starts, and because breaking and crushing the concrete will generate respirable crystalline silica over several days it is also assessed as high-risk processing of a crystalline silica substance, so a silica risk control plan is prepared and air monitoring is arranged, including at the boundary because there are neighbouring premises. A competent person designs the demolition sequence with exclusion zones, and a hazardous-materials survey confirms and removes a small quantity of asbestos lagging under the licensed regime before the structure is touched. During demolition, water suppression is applied continuously across the breaking face and at the mobile crusher, plant-and-pedestrian exclusion zones are maintained with a spotter, and operators and ground crew wear fit-tested P2 respirators, moving to powered air-purifying respirators for the sustained breaking. Slurry and suppression water are contained so they do not reach the stormwater system. Personal and boundary monitoring confirm the controls hold below the exposure standard, the records are retained, and the workers are enrolled in health monitoring with a registered medical practitioner.

Related legislation

• Model Work Health and Safety Act — primary duty of care; the duty to consult workers; the reckless-conduct offence; and notifiable-incident provisions, as enacted in each jurisdiction.
• Model Work Health and Safety Regulations — the high risk construction work provisions for demolition of load-bearing or structurally significant elements, the SWMS preparation and review duties, and the crystalline silica high-risk processing, silica risk control plan, air monitoring and health monitoring provisions, as enacted in each jurisdiction.
• Workplace exposure standard for respirable crystalline silica: 0.05 mg/m3 (eight-hour time-weighted average), which must not be exceeded; reframed as a workplace exposure limit from 1 December 2026.
• The licensed asbestos removal provisions, where asbestos is identified in the structure, require removal under the appropriate class of licence before demolition of the affected elements.
• Victoria operates under the Occupational Health and Safety Act 2004 and the Occupational Health and Safety Regulations 2017, with the demolition, silica and asbestos provisions and Compliance Codes applying in place of the model instruments.

Frequently asked questions