What Is Silica Dust? Risks, Controls & Awareness Training

Silica is a natural mineral found in sand, stone and soil. The form that matters at work is crystalline silica, and quartz is the most common type. It is in many everyday building materials, including concrete, brick, block, stone, mortar, tile and some engineered stone countertops.

Solid materials are not the problem. The hazard starts when they are cut, ground, drilled, sanded, crushed or blasted. That breaks the silica into very fine particles that float in the air. The smallest ones are invisible, so a work area can look clear and still be unsafe.

These fine particles are small enough to reach deep into your lungs, where your body cannot easily clear them.

Common tasks that create silica dust include:

• Cutting concrete, brick, block, pavers or tile with a saw
• Grinding or polishing concrete floors and walls
• Drilling or coring into concrete or masonry
• Chipping, jackhammering and demolition
• Abrasive blasting with sand or on concrete
• Cutting, grinding and polishing stone and engineered stone countertops
• Sanding drywall joint compound that contains silica, and mixing dry mortar or grout
• Sweeping or blowing off dusty surfaces

Smoking adds to the damage silica does to the lungs. Silica disease often develops slowly, so damage can build up for years before a worker notices symptoms such as shortness of breath or a lasting cough. Preventing exposure is the only real protection, and it starts with knowing which tasks create dust.

Good silica control follows the hierarchy of controls: start with the most effective options and use respirators as the last line of defence.

1. Eliminate or substitute. Plan the work to avoid cutting on site, or use materials and methods that create less dust.
2. Engineering controls. Use wet methods, such as water on the blade or bit, and tools with dust extraction shrouds connected to a suitable vacuum.
3. Safe work practices. Clean up with a HEPA vacuum or wet methods. Never dry sweep or use compressed air to blow dust off surfaces or clothing. Keep other workers away from dusty tasks.
4. Respirators. When dust cannot be controlled enough, wear the right respirator. It must fit properly, so a fit test is needed, and you must be clean-shaven where the seal meets your face.

Do not eat, drink or smoke in dusty areas, and change out of dusty clothes before going home.

Controls only work when they are used and kept in good shape. Check that the water supply is running before you cut, that vacuum hoses are attached and filters are not clogged, and that your respirator is clean and in good condition. If a control is missing or broken, stop and tell your supervisor.

Provincial OHS regulations require employers to control worker exposure to silica dust and to train workers who may be exposed. In plain words, where silica dust is created, employers are expected to assess the risk, keep exposure as low as reasonably possible, and have an exposure control plan that sets out the controls, the respirators to use, and how the work will be checked.

A good exposure control plan lists the tasks that create dust, the control used for each task, who is responsible, how workers are trained, and how the plan is reviewed. It should match what actually happens on site, not sit in a binder.

Supervisors must make sure the plan is followed on site. Workers must use the controls and PPE provided and report problems. The exact rules and exposure limits differ by province.

Anyone on a site where concrete, stone, brick or tile is cut, ground or drilled can be exposed, even if they are not doing the task themselves. Dust drifts, so a worker nearby can breathe in as much as the person holding the saw.

Supervisors benefit as much as workers. They plan the job, choose the tools, set up the controls and make sure the exposure control plan is followed, so they need to understand the hazard as well as the people doing the cutting.

Gama Safety’s Silica Awareness course has three modules:

1. Silica Awareness: The Hazard. What crystalline silica is, where it is found, which tasks create dust, and how it damages your lungs and health.
2. Controlling Exposure to Silica. How wet methods, dust extraction, HEPA vacuums, housekeeping and respirators keep exposure low.
3. Silica Legislation & Requirements. Exposure control plans and the legal duties of employers, supervisors and workers.

There is no single national expiry date. It depends on your province and employer. Many employers ask for a refresher every 1 to 3 years, and workers should be retrained when tools, tasks or the exposure control plan change.

1. Enrol in the online Silica Awareness course and start right away on any device.
2. Learn at your own pace. The course takes about 2 hours, and your progress saves automatically.
3. Pass the final exam with 80% or better. Retakes are unlimited and free.
4. Download your certificate right away. A physical wallet card is mailed to you free.

The course is available in English, French, Spanish, Punjabi, Hindi, Mandarin and more. Training a crew? Volume pricing starts at 2 seats, with an admin dashboard to track progress.