Control Measures to Protect Your Workers from Silica Dust
Silica, a natural substance found in rocks, sand, and clay (as well as certain plastics), can have a detrimental effect on an individual’s health (and can even be fatal) if inhaled into the lungs. Due to the abundance of silica in a wide range of useful materials, construction, mining and industrial workers are at a higher risk of exposure to silica dust. As an employer, you have a duty to protect your workers from exposure to crystalline silica, as this compound can generate harmful and respirable silica dust.
Here are some of our top tips for minimising the risks associated with silica dust in the workplace.
To manage the risks of silica dust, you must first identify whether it is, in fact, being generated and released into the air at your workplace. Then, do an assessment of what controls can be implemented. The appropriate control measures for your workplace will depend on your industry, work processes and the risk of exposure.
It’s important to provide 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. This includes isolating high dust generation work processes within an enclosed room with restricted access.
It’s also important to fit large machinery such as excavators and bulldozers with positive pressure enclosed cabs, sealing the outside environment and filtering air to prevent contaminants reaching the operator.
The best engineering controls for your workplace will depend on the tasks your workers undertake, and the extent to which these are generating respirable silica dust. It’s important to note that any uncontrolled processing of engineered stone that generates silica dust, including cutting, grinding or polishing with power tools or other mechanical plant, is not permitted in some states including Victoria.
The following are some engineering controls which implement physical methods to change the characteristics of a task in order to control dust:
- Automation: by automating cutting, grinding or drilling processes, exposure of workers to dust generated at the site is reduced
- Wet cutting: a wet method production process is likely to generate less dust than a dry one (dry cutting is banned in some states, including Victoria)
- On-tool/equipment dust control – drills, routers, saws and other equipment must be fitted with H-class local exhaust ventilation and a water attachment to suppress dust
- Local exhaust ventilation: this type of ventilation can be used to remove silica dust close to the source before it reaches the breathing zone of a worker
- Dust suppression: treating the dust on its transmission path by using drills, routers, saws and other equipment designed to be fitted with H-class local exhaust ventilation and a water attachment
Keep in mind that introducing some of these controls may inevitably introduce other hazards such as increased noise and vibration levels at your workplace, which will require additional mitigating control measures.
Ventilation, such as on-tool dust extraction and local exhaust ventilation, is a very effective engineering control when designed correctly. Your assessment of workplace and work activities will help to choose the right ventilation system to use to suit your site.
Workers require adequate training around silica dust hazards if they are working with silica or silica-containing products. They should be informed about what silica dust is and the health implications if it is inhaled, as well as what their risk of exposure is and the protective controls they must exercise to remain protected. Workers should also be encouraged to act if they observe unsafe work practices and to report any hazards in the workplace to help manage risks before illness occurs.
Training must be provided:
- As part of induction and refresher training
- When a worker will be carrying out a particular task or activity where silica dust is present or could be generated, and
- When significant changes are made at the workplace that affect how workers might be exposed.
The use of PPE is not as effective as implementing some of the aforementioned control measures, which are designed to prevent silica dust generation by minimising it at the source. PPE can however be used in conjunction with other controls to supplement preventative measures such as substitution (opting for materials with a lower silica content) or engineering controls.
Where PPE is provided, it must be appropriate and well-fitted to the worker to ensure silica dust cannot penetrate it to enter a worker’s eyes or breathing zone. Any PPE provided must also be clean, hygienic and in good working order.
Fit testing of respiratory protective equipment measures the effectiveness of the seal between the respirator and the wearer’s face. A good seal is required to ensure that any contaminated air, potentially containing silica dust, does not leak into the respirator to be breathed in by the worker. Fit testing can be carried out qualitatively or quantitatively, and by a competent person, manufacturer, supplier or consultant. Testing should also be repeated on a regular basis and based upon the outcomes of a risk assessment.
Air monitoring allows you to determine the airborne concentration of respirable crystalline silica at your workplace, and whether it exceeds the Australian workplace exposure standard of 0.05 mg/m3. By measuring the level of silica dust in the breathing zone of workers through monitoring on a regular basis, you can continually assess the risk to health and whether any current control measures are working effectively.
Exposure to silica dust can be eliminated or reduced even after work has stopped by adopting good housekeeping practices in your workplace. This might involve developing written rules and policies for workers requiring them to wet down dusty work areas and processes, or conduct a cleaning schedule for work areas and a maintenance schedule for engineering controls, for example. Housekeeping can be implemented as an administrative control measure for managing silica dust exposure.
As an employer, you must arrange health monitoring if there is a risk to the health of your workers because of exposure to silica dust. This includes workers who are not directly generating dust but are in the vicinity of silica dust or in contact with it in other ways, such as through cleaning work areas or equipment.
Silica Health monitoring must be carried out or supervised by an experienced doctor, and should be undertaken at different intervals during a worker’s employment:
- Completed in pre-employment assessments (before a worker starts with the company)
- On an ongoing basis, health surveillance testing can detect any changes to a worker’s health
- As part of exit health testing when a worker leaves a company
If you would like to learn more about how to protect your team from exposure to silica dust, get in touch with us today.