Respirable Crystalline Silica — Workplace Exposure Limit Change

CAS: 14808-60-7 | Notation: Respirable fraction, carcinogen (IARC Group 1)

Current WES

0.05

mg/m³

New WEL (Dec 2026)

0.025

mg/m³

Change

-50%

reduction

Health Effects

Respirable crystalline silica is classified as a Group 1 carcinogen by IARC, with sufficient evidence of causing lung cancer in humans. Chronic inhalation causes silicosis, an irreversible and progressive fibrotic lung disease that reduces lung capacity and can be fatal. Accelerated silicosis develops after 5 to 15 years of moderate exposure, while acute silicosis can develop within months following very high exposure events such as dry cutting engineered stone without controls. Silica exposure is also associated with chronic obstructive pulmonary disease, kidney disease, and autoimmune conditions including scleroderma and rheumatoid arthritis. Australia's engineered stone crisis, which prompted a national ban on engineered stone benchtop fabrication from 1 July 2024, demonstrated the devastating health consequences of inadequate silica control.

Where Exposure Occurs

Cutting, grinding, and drilling concrete, brick, and masonryTunnelling and underground mining operationsConcrete finishing and polishingSandblasting and abrasive blasting with silica-containing mediaDemolition of concrete and masonry structuresQuarrying and crushing of silica-containing rock

What to Do Now

01Conduct baseline respirable crystalline silica air monitoring at all tasks involving cutting, grinding, drilling, or demolition of concrete, masonry, brick, and natural stone. Use personal sampling with a cyclone sampler to capture the respirable fraction. Many tasks that were borderline compliant at 0.05 mg/m³ will exceed the new 0.025 mg/m³ WEL.

02Implement wet suppression as the primary engineering control for all silica-generating tasks. Water suppression at the point of cutting or grinding reduces airborne silica concentrations by 80 to 95 per cent depending on the application rate and method. Dry cutting of silica-containing materials should be eliminated wherever practicable.

03Establish or update the silica worker register required under the WHS Regulation 2025. The register must record each worker's exposure history, health monitoring results, and the controls in place for each silica-generating task. Records must be retained for 40 years after the last entry to account for the long latency period of silica-related diseases.

04Implement a health surveillance program including baseline and periodic chest X-rays, lung function testing, and symptom questionnaires. Health monitoring must be offered to all workers who carry out silica-generating work and must be conducted by a registered medical practitioner with experience in occupational respiratory disease.

05Review and upgrade RPE programs. P2 disposable respirators provide an assigned protection factor of 10, meaning they are suitable only where exposures are below 0.25 mg/m³ under the new WEL. Tasks generating higher concentrations require half-face or full-face respirators with P3 filters, or powered air-purifying respirators. All RPE must be fit-tested to the individual worker.

Monitoring Method

Personal air sampling using a calibrated pump at 2.2 L/min with a cyclone pre-selector (Higgins-Dewell or SKC aluminium cyclone) and pre-weighed 25mm or 37mm PVC filter. Analysis by X-ray diffraction (XRD) following AS 2985 or NIOSH Method 7500. Gravimetric analysis alone is insufficient — crystalline silica must be quantified by XRD or FTIR.

Affected Industries

Construction →Metal Fabrication →

Measure exposure against the right limit

OH Consultant designs and runs personal exposure monitoring for respirable crystalline silica, reviewed by a Certified Industrial Hygienist, and reports results against the limit that applies to your site, whether the 1 December 2026 WHS WEL or a mine-specific limit.

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