Crystalline silica technical fact sheet
The technical fact sheet helps you manage the risks of working with crystalline silica.
Crystalline silica is a very common mineral used in manufacturing building products in construction materials. Applying adequate controls such as minimising the generation of airborne dust can reduce hazardous exposures and prevent illness in the workplace.
A priority list of 100 chemicals, following national and international research, was developed in which Crystalline Silica ranked second.
Sources of exposure
Materials and products containing crystalline silica include shale, sandstone, concrete, bricks and manufactured stone. Workers can come across crystalline silica during excavation or tunnelling through quartz containing rock such as shale or sandstone. A health hazard is created when the very fine particles of crystalline silica can be inhaled. The size fraction of airborne dust that can reach the lungs where air exchange takes place is known as the 'respirable fraction'. Once particles become larger than about seven microns (1 micron = 1/1000 mm) in diameter, they are no longer respirable.
Significant levels of airborne dust are most likely to occur when materials or products in the workplace are cut, sanded, drilled or during any other activities which create fine dust. Exposures in workplaces can also occur through dry sweeping or using compressed air (rather than wet cleaning or using a Class M or H vacuum) and re-suspension of settled dust from clothing or fabric materials.
Respirable crystalline silica (RCS), depending on factors such as how much dust a worker breathes in and for how long, can cause silicosis. Silicosis is a fibrosis (scarring) of the lung resulting in loss of lung function. This fibrosis is incurable and continues to develop after exposure has stopped. Persons with advanced silicosis suffer severe shortness of breath and may suffer complications such as heart failure.
Silicosis can be classed into:
- chronic (or classic) silicosis, typically observed in workers following ten years or more exposure
- accelerated silicosis, appearing in workers after high exposure over a shorter period of time (one to ten years)
- acute silicosis, observed in workers usually less than one year after exposure to silica at very high concentrations. Acute silicosis can cause very serious health effects and is life threatening.
Significant long term exposure to crystalline silica has also been associated with an increased risk of developing lung cancer.
Labelling and safety data sheets
Manufacturers and importers need to label their products if they contain 0.1% or more respirable crystalline and provide a current Safety Data Sheet (SDS) clauses 329, 330 and 335 WHS Regulation 2017). Suppliers must ensure these products are correctly labelled when suppled to workplaces and provide an SDS (clauses 338 and 339).
A person conducting a business or undertaking (PCBU) must also obtain a copy of the SDS and make it readily accessible to workers involved in using, handling or storing the hazardous chemical at the workplace (cl 344). Manufacturers, importers and suppliers must also determine if workers can be exposed to respirable crystalline silica when working with products they manufacture, import or supply that contain crystalline silica (for example, by cutting or grinding the product. Where exposure to RCS can occur, adequate information must be given to each person the product is provided to, outlining the conditions necessary to ensure it can be used without a risk to health and safety.
Workplace exposure standards and air monitoring
Respirable crystalline silica has a workplace exposure standard of 0.05 mg/m3 averaged over eight hours. Risks to health and safety from exposures to hazardous chemicals must, so far as is reasonably practicable, be eliminated. PCBU’s must ensure that no person at the workplace is exposed to a substance above its exposure standard and must reduce exposures so far as is reasonably practicable.
PCBU’s must undertake personal exposure (air) monitoring for substances with an exposure standard if they are not certain (on reasonable grounds) as to whether or not the exposure standard is exceeded.
Adjustments to the exposure standards are made for extended work shifts, taking into account the longer daily exposure. Air monitoring results must be readily available to workers and records of results kept for 30 years (cl 50).
PCBU’s are required to provide health monitoring to workers if there is a significant risk to the worker’s health because of exposure to crystalline silica. (cl 368)
Crystalline silica is listed in Schedule 14 of the WHS Regulation 2017 which outlines the health monitoring requirements.
In relation to health monitoring, PCBU (clauses 369 to 378) duties include:
- informing workers of the requirements for health monitoring
- using a registered medical practitioner with experience in health monitoring
- providing details to the medical practitioner
- obtaining a copy of the health monitoring report
- providing a copy of the health monitoring report to SafeWork NSW if the worker has developed a disease or injury and/or the report contains any recommendations on remedial measures at the workplace
- keeping records of health monitoring for 30 years.
Workers exposed to respirable crystalline silica at levels or a frequency not resulting in a significant risk to health, are not required to undergo health monitoring. Workers relying on personal protective equipment (PPE) such as respirators for controlling their exposures below the exposure standard must be included in health monitoring.
Where risks to health and safety cannot be eliminated the hierarchy of controls must be applied in accordance with the WHS Regulation to minimise risk. For instance:
- apply water suppression systems to reduce dust generation
- use local exhaust ventilation systems to remove dust at the source
- ensure such ventilation is correctly placed and operates at effective flow rates
- use dust removal systems on tools to reduce dust exposure to mobile workers
- isolate areas of the workplace where dust is generated
- assess the level of personal exposure among workers performing high risk tasks
- ensure regular housekeeping in dusty work areas to prevent the accumulation of dust
- provide suitable PPE, including a program to correctly fit, instruct on use and ensure regular maintenance of respiratory protective equipment (RPE).
Clause 184 (O) prohibits the uncontrolled cutting, polishing, grinding or drilling of manufactured stone products (also known as engineered or composite stone) in fabricating workshops or on site. At least one of the following controls to effectively reduce exposure to the dust must be in place:
(i) a water delivery system that supplies a continuous feed of water over the area being cut to suppress the generation of dust,
(ii) a prescribed extraction system (e.g. class M or H vacuum) that is attached to the tool used for the cutting to capture the dust produced by the cutting,
(iii) a local exhaust ventilation system that captures the dust produced by the cutting and transports the dust to a safe emission point or to a filter or scrubber.
Workers must also be provided with and wear half face piece respirators. as a minimum, that comply with Australian Stansdard 1716 - Respiratory Protective Devices.
PCBU’s must provide suitable information, training, instruction and supervision to workers using, storing and handling hazardous chemicals regarding the nature of the work, risks and the control measures implemented (cl. 39 and 379).
PCBU's with duties under the WHS Regulation 2017 must review and revise control measures, as necessary, to maintain a work environment so far as reasonably practicable, that is without risk to health or safety (cl 38).
Codes of practice
These codes of practice provide more detailed information on how you can achieve the standards required:
- Managing the risks of hazardous chemicals in the workplace (PDF, 1171.43 KB)
- Preparation of safety data sheets for hazardous chemicals (PDF, 3030.68 KB)
- Labelling of workplace hazardous chemicals (PDF, 1176.83 KB)
- Construction work (PDF, 1014.41 KB)
Safe Work Australia guidance material
- Workplace exposure standards for airborne contaminants (2022)
- Guidance on the interpretation of Workplace exposure standards for airborne contaminants
- Health monitoring for persons conducting a business or undertaking guide
- Health monitoring when you work with hazardous chemicals guide
- Guide for tunnelling work
- AS/NZS 1715-2009 Selection, use and maintenance of respiratory protection
- AS/2985-2009 Workplace atmospheres method for sampling and gravimetric determination of respirable dust