Workers and management can work together to reduce exposure to crystalline silica dust. Businesses must manage risks to workers’ health and safety and workers must also take steps to protect themselves. A safe place of work benefits everyone.
To meet the workplace exposure standard, you should follow a risk management process to identify risks and the measures you can use in your workplace to minimise the amount of dust workers are exposed to.
The Working with crystalline silica substances: Guide will help the industry to understand the additional work health and safety requirements in relation to the processing of crystalline silica substances (CSS) and ways to protect workers and others at the workplace from respirable crystalline silica (RCS).
If you are working in the stone benchtop industry, you must comply with the Managing the risks of respirable crystalline silica from engineered stone in the workplace: Code of practice. The code provides detailed, practical guidance on how to manage the risks associated with respirable crystalline silica.
Learn how to manage risks associated with working with engineered stone.
Step 1: Identify the hazard
To manage risks of exposure to RCS at work, you must first identify whether any processing of a CSS is being carried out at the workplace. Carrying out processing of a CSS can generate and release RCS into the air, which can expose workers and others at the workplace to RCS, if not controlled effectively. This can occur across a broad range of workplaces and industries including manufacturing, stonemasonry, construction, tunnelling and demolition.
Examples of types of work that involve the processing of a CSS include, but not limited to:
- excavation, earth moving and drilling plant operations
- clay, sand and stone processing machine operations
- cutting and laying pavers and surfacing
- road construction and tunnelling
- construction, building and demolition involving a CSS
- brick, concrete or stone cutting
- abrasive blasting (blasting agent must not contain greater than 1 per cent of crystalline silica)
- foundry casting
- angle grinding, jack hammering and chiselling of concrete or masonry
- hydraulic fracturing of gas and oil wells
- pottery
- crushing, loading, hauling and dumping of rock, or muck from tunnelling
- clean up activities such as sweeping or pressurised air blowing of dust containing crystalline silica.
The following examples give an indication of the varying levels of crystalline silica in different products:
- engineered stone: up to 97%
- sandstone: 70–90%
- granite: 25–60%
- ceramic tiles: 5–45%
- autoclaved aerated concrete: 20–40%
- Slate: 20–40%
- concrete: less than 30%
- porcelain: 14–18%
- brick: 5–15%
- marble: 2%
You can check safety data sheets and other information from suppliers to find out whether products contain crystalline silica.
Identify where and how dust from these products is being released at your place of work. This may be achieved by:
- conducting a walk-through assessment of the workplace
- observing the work and talking to workers and/or HSRs about how work is carried out
- inspecting the plant and equipment that is used as part of the fabrication and other relevant processes – for example, hand-held tools may generate more silica dust than automated machinery
- undertaking air monitoring at the workplace
- inspecting workplace surfaces for build-up of settled dust, and
- reading product labels, safety data sheets and manufacturers’ instruction manuals.
Step 2: Assess the risk
A risk assessment involves considering what could happen if a worker is exposed to a hazard and the likelihood of it happening. Exposure to silica dust can adversely affect a worker’s health, including developing silicosis, progressive massive fibrosis, chronic obstructive pulmonary disease, chronic bronchitis, and lung cancer.
A PCBU must assess the processing of a CSS carried out by the business or undertaking at the workplace to determine if the processing is high risk. This assessment must consider the forms of crystalline silica present in the CSS, it's concentration (weight/weight), hazards associated with work including frequency and duration of exposure, any relevant air or health monitoring details,
If you have identified silica, assess the risks by carrying out a risk assessment. The risk of silica exposure from the task is assessed by examining the work processes involving crystalline silica. The assessment must consider the dust exposure that could occur. Having dust levels monitored is the most accurate way to assess the risk, however in some cases (e.g. where there are visible clouds of dust from high silica materials, such as during dry concrete cutting) the risk may be clear without monitoring. It should be noted that very fine particles may be difficult to see in air, and monitoring is required to assess the risk from such particles.
Silica risk control plan
A silica risk control plan is a practical tool to document the specific tasks and control measures related to each processing of a CSS that is high risk carried out by the PCBU. If you have assessed the processing of a CSS, or a combination of processing of a CSS, as being high risk, you must develop a silica risk control plan covering those processing tasks. This must be available for all workers to access before they commence the processing of a CSS.
A template for a silica risk control plan is provided in the Working with crystalline silica substances: Guide or refer to completing a silica risk control plan by Safe Work Australia.
Step 3: Control risks
- 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
Step 4: Review risk controls
You should regularly review your control measures to make sure they remain effective for managing your workplace risks.
For example, a PCBU should conduct daily start up checks to ensure that:
- machine and water mist guards and LEV are fitted correctly and are working effectively
- LEV filters are clean and replaced according to the manufacturer’s instructions
- there is an adequate water supply for water suppression
- all respiratory protective equipment (RPE) is in good, working condition and fit checked.
A PCBU should routinely monitor the workplace for signs of visible dust on work surfaces or clothing as that may be an indication that some controls are not working effectively.