According to a 2021 report by the Government's National Dust Disease Taskforce, nearly one in four workers exposed to silica dust from engineered stone before 2018 have been diagnosed with silicosis or other silica dust-related diseases. This number is predicted to rise, most notably among young men.
 
As recommended by the taskforce, specialists in respiratory, sleep, occupational and environmental medicine will be required to notify the registry of every diagnosis of occupationally caused silicosis. They may also notify the registry of other occupational respiratory diseases, with the patient’s consent.
 
Assistant Federal Health Minister the Hon Ged Kearney MP says the registry is an important next step in supporting the early detection and prevention of workplace risks and developing strategies to protect workers from further exposure. 

“We are acting now to ensure workplace safety authorities have accurate information about the number and types of cases of occupational respiratory diseases,” she says.
 
Information from the national registry will be disclosed to state and territory authorities. 

The Government has committed $2.4 million for the registry operation to 2025–26. 

What is silica dust?  

Silica dust is prevalent in industries such as mining, quarrying, construction and manufacturing. 

It is generated in workplace mechanical processes such as crushing, cutting, drilling, grinding, sawing or polishing of natural stone or artificial products that contain silica. Some dust particles can be so small that they are not visible; these are commonly referred to as respirable particles.  

Respirable silica dust particles are small enough to penetrate deep into the lungs and can cause irreversible lung damage.  

The non-crystalline or amorphous forms of silica do not cause this kind of lung damage. 

High-risk exposure 

Crystalline silica is most dangerous to health when dust is generated, becomes airborne and is then inhaled by a worker.  

Examples of work activities at high risk include:  

• during fabrication and installation of composite (engineered or manufactured) stone countertops  
• excavation, earth moving and drilling plant operations  
• clay and stone processing machine operations  
• paving and surfacing  
• mining, quarrying and mineral ore treating processes  
• tunnelling  
• construction labouring activities  
• brick, concrete or stone cutting; especially using dry methods  
• abrasive blasting (blasting agent must not contain greater than 1% of crystalline silica)  
• foundry casting  
• angle grinding, jack hammering and chiselling of concrete or masonry  
• hydraulic fracturing of gas and oil wells, and  
• pottery making.  

What’s the best control measure? 

Under the WHS Regulations (WA) 2022, businesses have specific duties to manage the risks to health and safety when using, handling, generating and storing hazardous chemicals, including silica. There is also a duty to ensure the workplace exposure standard for crystalline silica is not exceeded and to provide health monitoring to workers.  

Managing risks and worker exposures to silica can be achieved by a number of control measures. Some of these recommendations, according to Worksafe WA include: 

• Choosing materials (e.g., abrasive blasting agents) that are silica free or have the lowest silica content  
• Designing buildings with recesses for services to reduce the amount of chasing required  
• Providing vehicles with enclosed cabs fitted with high efficiency air filters, for dusty earthworks or mining   
• Using wet work methods to reduce dust (e.g., wet cutting or polishing, water sprays during earthworks)  
• Using water spray or rubber curtains around conveyor transfer points  
• Using local extraction ventilation, either fixed or on-tool (e.g., for mixing, crushing, milling, drilling or chasing)  
• Shadow vacuuming (e.g., during drilling)  
• Vacuum clean-up rather than sweeping  
• Not blowing dust with compressed air 
• In addition to other controls, PPE such as an appropriate respirator (selected in accordance with Australian/New Zealand Standard AS/NZS 1715: Selection use and maintenance of respiratory protective equipment) may be required, depending on the task and the effectiveness of the other controls  

More than one control will normally be required to adequately protect workers.  

The workplace exposure standard  

Respirable crystalline silica (silica dust) is classified as a hazardous chemical according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and has a workplace exposure standard.

The workplace exposure standard for silica dust that must not be exceeded is 0.05 mg/m3 (eight-hour time weighted average).  

Worker exposure to silica dust should be kept as low as reasonably practicable. Air monitoring must be conducted if there is any uncertainty that the exposure standard is being exceeded or to find out if there is a risk to a worker’s health.

Health monitoring for workers 

The minimum health monitoring requirements for crystalline silica include:  

• collection of demographic, medical and occupational history  
• records of personal exposure  
• standardised respiratory questionnaire  
• standardised respiratory function tests, for example, FEV1, FVC and FEV1/FVC, and  
• chest x-ray full posterior to anterior view (baseline and high-risk workers only).  

It is very important for PCBUs and workers to understand the nature of this hazard and the risks associated with it.

Our qualified workplace health and safety experts provide cost-effective solutions to manage your WHS needs, reduce the risk to your workers and help you meet WA’s WHS laws. Email [email protected] or call (08) 9365 7746.