Exposure to silica dust is highly hazardous and can result in injury, illness and disease. We typically associate Black Lung Disease with coal mining and much has been researched and written about this disease. However, exposure to silica dust and asbestos can result in silicosis. The symptoms are very similar. Silica is silicon dioxide that you can find in many rocks and soils, for example, quartz.
In Australia, we are developing large tracts of land, building major infrastructure road projects, mining, and have a love for stone benchtops in our homes. All of these activities expose workers to silica dust hazards. For this article, we take a look at Safe Work Australia’s National Guidance Material to outline silica dust hazards and provide some mitigation strategies.
What Can Happen if We Expose Workers to Silica Dust?
Exposure to silica dust can lead to several immediate symptoms and long term health problems including:
- Irritated eyes and damage over time
- Breathing problems
- Chronic bronchitis
- Lung cancer
The problem is that silicosis is irreversible, and symptoms may not appear for years after the initial exposure. Silicosis is a severe health problem for workers. It is also a concern for organisations because health claims from past employees can develop years after they left the business. Prevention and health monitoring are critical.
The Cancer Council of Australia reports that in 2011, approximately 587,000 Australian workers were exposed to silica dust in the workplace. They estimate that 5,758 of these will develop lung cancer throughout their life as a result of that exposure.
How is Airborne Silica Dust Generated?
Workplace processes such as crushing, cutting, drilling, grinding, sanding, sawing or polishing of natural stone or man-made silica-containing products, generate silica dust. Respirable silica dust particles are those that are small enough to breathe in and penetrate deep into the lungs causing permanent damage that can lead to serious illness. Dust particles can hang in the air for a long time, even after we finish the work.
We find silica dust:
- in waste or sand-based products, and
- in materials brought to your workplace.
We create silica dust:
- during manufacturing and construction, and
- when mining or tunnelling.
What You Should Do to Control Silica Dust Hazards
Because it’s hard to see respirable silica dust it is critical that you monitor the air. Keep under the workplace exposure standard of 0.1 mg/m3. You should also keep all records of air monitoring for 30 years.
If there is a risk of exposure to silica dust for your employees, you must regularly monitor their health, and it is the onus of the organisation to pay for health monitoring. From the time that your employees begin work with your organisation, you should monitor their health so that you get a baseline. A starting point helps to track any changes in the future.
Working according to the hierarchy of controls, whenever possible, you should eliminate the need to work with silica dust emitting products or substitute for alternatives. However, you can’t always achieve the higher-level controls of elimination and substitution. For example, when you are working on infrastructure projects that are moving sand.
Isolating workers from high-dust areas is an effective way of protecting them from exposure. Physical barriers, exclusion zones, providing dedicated rooms or areas or using water mists can shield workers from silica dust.
Engineering controls include using wet cutting methods, providing ventilation, vacuuming up dust as soon as possible, and using heavy mobile equipment with enclosed cabs. Effective housekeeping measures come into play here because dust is not only a health hazard; it is also abrasive and can damage equipment and machinery.
You should use the lower-level controls of administrative controls and PPE, in conjunction with the four measures we have discussed. Administrative controls include job rotation, ensuring cutting tasks are planned to use the minimum number to get the job done, and restricting access to high-dust areas that are clearly signed.
You should provide PPE including dust masks, breathing apparatus, gloves and eye protection. Dusty PPE should not be taken home, should be placed in designated areas and sent off for cleaning. Facial hair can interfere with respirators and employees should be clean-shaven.
See our article, What Are Your Workplace Health and Safety Obligations?
Training is a Critical Step
If your organisation conducts activities that produce silica dust, you need to train your employees about the hazards. Training starts at the induction and should continue with ongoing refresher training. Employees need to learn about the most effective dust mitigation strategies, how to protect themselves and the symptoms of silica dust exposure.
Training should include how to wear and correctly fit their PPE to ensure that it provides the best protection to dust exposure. Because every person’s face is a different shape, correct fit becomes especially important when fitting respirators. PPE should be clean, in good working order and regularly replaced.
Tap into Safety includes silica dust and dust hazards in a number of our out of the box safety training courses including:
See our article, Can Employees Recognise, Recall and Report Workplace Hazards?
Exposure to silica dust has both immediate and long-term consequences. The problem is respirable dust particles that can lead to most harm are often undetectable by the naked eye and hang around in the air for long periods.
Organisations that perform work that creates dust including mining, construction and infrastructure work must recognise, address and train about silica dust hazards. The hierarchy of controls is the best way to manage silica dust hazards and to reduce exposure.