Silica is the scientific name for a group of minerals made of silicon and oxygen. Silica is found in most mineral deposits in the world in both crystalline and non-crystalline (amorphous) forms.
Crystalline silica has its oxygen and silicon atoms arranged in a three-dimensional repeating pattern. Amorphous forms of silica have a random pattern.
Crystalline silica occurs in several forms, including quartz, cristobalite and tridymite. Quartz is the most common form of crystalline silica.
It is the crystalline form of silica that is the main concern when considering health effects.
Click here to open Crystalline Silica at the Work Site Alberta Report
Silica is one of the most common hazards on a worksite, particularly in the construction, oil and gas, manufacturing, and agriculture industries.
Silica dust can cause silicosis, a serious and irreversible lung disease. It can also cause lung cancer. Cutting, breaking, crushing, drilling, grinding, or blasting concrete or stone releases the dust. As workers breathe in the dust the silica settles in their lungs.
For information on protecting workers from harmful exposure to silica dust, see the resources section below, which includes a silica control tool.
How workers are exposed:
Silica is the basic component in sand and rock. It’s in construction materials such as:
- Concrete, concrete block, cement, and mortar
- Masonry, tiles, brick, and refractory brick
- Granite, sand, fill dirt, and top soil
- Asphalt-containing rock or stone
- Abrasive used for blasting
Silica is the most common hazard on a work site. Any activity that creates dust can expose workers to airborne silica. The most common ways to create silica dust are as follows:
- Chipping, sawing, grinding, hammering, or drilling
- Crushing, loading, hauling, or dumping
- Building demolition
- Power cutting or dressing stone
- Facade renovation, including tuck-point work
- Abrasive or hydro blasting
- Dry sweeping or pressurized air blowing
- Tunneling, excavating, or earth moving
The risks
Inhaling silica dust can cause silicosis, a serious and irreversible lung disease. It can be lethal. Silica damages the lung and causes scar tissue to form. This causes the lung tissue to become thicker. Silica exposure can also cause lung cancer.
It is possible to have silicosis without showing any symptoms at first. The longer workers have been exposed to silica dust, the worse the symptoms will become. As the disease progresses workers may show noticeable symptoms such as:
- Shortness of breath
- Severe coughing
- Body weakness
How to reduce the risks
The best way to reduce the risk of exposure to silica dust is to eliminate the source of exposure.
If that’s not possible, there are other risk controls to use.
When choosing risk controls, start by asking the questions in the following steps.
The steps are listed in order of effectiveness.
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