Choosing and implementing control measures for respirable crystalline silica

Safe Work Australia has published the Decision Regulation Impact Statement: Prohibition on the use of engineered stone (Decision RIS). Read the Decision RIS and questions and answers to learn more.

Elimination 

Elimination means you completely remove the hazard from your workplace. 

If it is reasonably practicable, eliminate the risk of RCS exposure at your workplace. You can eliminate RCS at the source by eliminating the product or processes that generate dust. For example:

  • eliminating silica-containing products from the workplace, or
  • using a product that does not need to be modified. This will remove the risk of workers being exposed to RCS when working with these products.

Substitution 

Substitution is where you replace a product or chemical with something that is less hazardous and therefore has a lower risk. 

Effective substitution of crystalline silica and silica containing products will depend on your workplace and the work tasks your workers carry out. Again, substitution might not be practicable where crystalline silica is naturally occurring or if it means you can’t make the end product or deliver a service. 

Substitution can be an effective way of managing the risk of exposure to RCS. For example, you can: 

  • use products that do not contain crystalline silica or have low levels of crystalline silica, or
  • use a liquid or paste form of a silica product. 

Isolate workers and others from RCS 

Isolation is where you place barriers or distance between a hazard and workers. 

Isolation is an effective way of protecting your workers from exposure to RCS. Physical barriers that remove the worker from contact with RCS are the most effective form of isolation controls. 

Isolation controls include: 

  • isolating high dust generating work processes within an enclosed room with restricted access
  • providing physical barriers and exclusion zones between different workers and workstations to prevent dust or water mist from moving into other work areas or towards other workers 
  • distancing a work process from other workers. 
  • for example consider where other workers are working when powered hand tools are used 
  • designating a room or area for other tasks such as changing or eating, away from the work area. 

You can also use barriers around automated tasks to shield workers from RCS. 

Wherever possible, workers should not cut, grind or polish silica containing products at the installation site. If modifications at the installation site need to be made, this work should be done outdoors in a designated area, wearing appropriate PPE and using engineering controls, including wet methods and dust collection systems. 

Engineering controls 

Engineering controls use physical methods to reduce the risk of exposure to a hazard. The best engineering controls for your workplace will depend on the tasks your workers carry out. 

Engineering controls that may be used to control RCS include: 

  • automation when cutting, grinding or drilling 
  • using wet processing methods 
  • local exhaust ventilation 
  • drills, routers, saws and other equipment fitted with on-tool dust extraction and a water attachment to suppress dust 
  • using sacrificial backer-boards or spoil boards 
  • fitting large machinery such as excavators and bulldozers with positive pressure enclosed cabs, and 
  • cleaning up dust with a M or H-class industrial vacuum cleaner. 

A PCBU must ensure that processing of engineered stone is controlled using at least one of the following engineering controls: 

  • a water delivery system that supplies a continuous feed of water over the stone being processed to suppress the generation of dust
  • an on-tool dust extraction system
  • a local exhaust ventilation system.

All workers who process engineered stone must also be provided with RPE.

When considering and using engineering controls, be aware of other hazards that may be introduced. As many engineering controls are motorised you should be aware of noise and vibration levels at your workplace and issue personal hearing protection as needed. 

RCS and other dusts are abrasive and can damage and wear engineering controls. It is important to have a maintenance schedule in place to keep your equipment in good working order. You should regularly inspect your equipment for: 

  • wear and tear, corrosion or damaged parts 
  • air leaks in pneumatic tools 
  • kinks, holes or leaks in water suppression or dust extraction equipment, or 
  • damage to guards and flaps that contain water spray. 

More information about engineering controls can be found in:

Administrative controls 

Administrative controls should only be used to provide additional protection and must only be considered after implementing substitution, isolation and engineering controls. 

Administrative controls rely on worker behaviour and it is very important to have administrative policies and worker training when crystalline silica is identified at your workplace. You also need to supervise your workers to make sure they understand and follow your administrative policies. 

Examples of administrative controls for RCS include: 

  • planning cutting tasks to make sure the minimum number of cuts are made 
  • written rules and policies for working with silica or cleaning silica waste, for example having a written clean-up procedure and log
  • shift rotation policies to make sure workers are not exposed to RCS above the workplace exposure standard and for extended periods of time
  • providing a laundry service for dusty PPE and work wear supported by a policy outlining:
    • that dusty PPE and work wear are not to be taken home
    • designated areas where dusty PPE and clothes must be changed
    • when dusty PPE and clothes must be laundered
  • policies for storage, cleaning and maintenance of equipment
  • signage at the workplace highlighting there is a dust hazard and any required use of PPE, including RPE, and
  • restricted area policies so that only staff who are trained to safely carry out a task that generates RCS are allowed access to high risk areas.

Training 

When you are working with silica-containing products, you must talk to workers about RCS hazards. Training must be provided: 

  • as part of induction and refresher training 
  • when a worker will be carrying out a particular task or activity where RCS is present or could be generated, and 
  • when significant changes are made at the workplace that change how workers might be exposed. 

The information you give to workers during training should give them a good understanding of: 

  • what RCS is and its health effects 
  • what controls are in place to protect them 
  • when they might be at risk of exposure including: 
    • bad work practices, or
    • when controls might not be effective, and
  • what to do if they observe unsafe practices at the workplace.

You should encourage your workers to report hazards and health and safety problems immediately. This is important because it allows the risks to be managed before an incident or illness occurs. 

Housekeeping 

Good housekeeping can eliminate or reduce exposure to RCS, even after work has stopped. Developing written rules and policies for your workplace is a good way to implement housekeeping as an administrative control. For example you could require your workers to: 

  • wet down dusty work areas and processes 
  • conduct a cleaning schedule for work areas and a maintenance schedule for engineering controls 
    • for example regularly cleaning dusty vehicle track or high use areas and keep them wet during the day 
  • carry out daily cleaning procedures for slurry and settled dust 
  • for example placing wet slurry inside a sealed container for disposal 
  • never use compressed air, dry sweeping or general purpose vacuum cleaners to clean surfaces or clothing 
  • use a low pressure water, wet sweeping or a M or H class rated vacuum cleaner to clean dusty floors, walls, other surfaces and equipment, and 
  • always follow the vacuum manufacturer’s operator manuals and instructions for changing dust bags and filters. 

If your workers are outdoors, you can cover the ground with plastic sheeting and remove remaining dust using the above methods. 

Decontamination 

Dusty clothing and PPE can expose workers and others to RCS. Examples of how you can minimise exposure to RCS carried on PPE and work clothes include: 

  • using an industrial H class vacuum cleaner to remove dust from clothes and uniforms 
    • by positioning these units at the exits of dusty work areas, you can encourage workers to vacuum their clothes before leaving
    • you should make sure that workers have access to an area to wash their arms, hands, faces and even their hair. 
  • providing a laundry service for dusty work clothes and PPE so they are not taken home for washing
    • if you use a commercial laundry, dampen the clothes and place them in a sealed, labelled plastic bag, and inform the laundry that the clothes are contaminated with crystalline silica 
  • requiring workers to change dusty clothing after each shift, or if they have just finished a very dusty task to change at their next break, and 
  • providing workers with rubber boots and aprons. 

Workers' clothes and uniforms must be cleaned frequently to stop RCS from contaminating break rooms, other parts of the workplace and importantly, to stop workers from taking RCS home. 

More information about facilities at your workplace can be found in the model Code of Practice: Managing the work environment and facilities. 

Personal protective equipment 

You should never rely solely on PPE to protect workers from RCS. 

Before using PPE you need to do a risk assessment to see what other controls can and should be used. PPE should only be considered after implementing substitution, isolation, engineering and administrative controls. It should only be used to supplement higher-level control measures or when no other safety measures are available. 

There are requirements under the WHS laws when it comes to choosing and using PPE. 

As RCS particles are very small, workers should be provided with appropriate RPE. As everyone's face is a different size and shape, there is no 'one size fits all' respirator. Fit testing is essential to make sure the RPE works correctly and is comfortable to wear with other PPE that may be needed for the task.

More information on appropriate RPE and fit testing is available in the model Code of Practice: Managing the risks of respirable crystalline silica from engineered stone in the workplace.

You must make sure the PPE you provide is appropriate and fits the worker who will be wearing it. This will ensure that the PPE is doing its job. Wrong or ill-fitting PPE means that RCS can harm your workers. For example the dust can get into worker’s eyes or into the worker’s breathing zone and into their lungs. 

You must make sure PPE is clean, hygienic and in good working order. This is so that you do not introduce other hazards to the worker and that the PPE will work as intended. Information about maintaining and cleaning PPE should be sourced from the manufacturer or supplier. 

You must provide ongoing training, information and instructions for your workers on how to use, clean and store the PPE you provide.

Workers must take reasonable care for their own health and safety. They are expected to follow reasonable instructions and cooperate with any workplace policies you have in place to protect them. Workers must use and wear PPE as instructed by you. However, you must also supervise your workers to check they understand their training and are using the PPE correctly. 

You can find more information on PPE, including RPE and fit testing, on the Personal protective equipment (PPE) web page and in the Working with silica and silica containing products guide.

Prohibition on the uncontrolled processing of engineered stone

A PCBU must ensure that processing of engineered stone is controlled using at least one of the following systems: 

  • a water delivery system that supplies a continuous feed of water over the stone being processed to suppress the generation of dust
  • an on-tool dust extraction system
  • a local exhaust ventilation system.

All workers who process engineered stone must also be provided with RPE.

PCBUs should consider if additional control measures are required to eliminate or minimise the risk of RCS and to ensure the workplace exposure standard is not exceeded. A PCBU should conduct air monitoring to check the effectiveness of any the control measures implemented to control RCS.

Supporting information