What is silica dust? Silica (silicon dioxide, SiO2) is one of Earth’s most abundant compounds, formed when silicon bonds with oxygen. In nature it appears in several crystalline polymorphs: quartz (by far the most common), cristobalite, and tridymite, as well as less common forms like coesite and stishovite. When stone is broken, cut, or the form is otherwise altered, silica dust is released and can severely harm the wellbeing of those exposed.
Materials that typically contain silica:
- Sand and sandstone
- Concrete nd mortar
- Asphalt mixtures
- Brick, tile, and ceramics
- Glass and fiberglass
- Natural stone (granite, slate, marble, flint)
- Industrial fillers and composite plastics (tires, electronic encapsulants)
Common activities that generate respirable silica dust:
Sawing, jack hammering, crushing, milling, grading, earth moving, sweeping, abrasive blasting, and hydraulic fracturing all chip or grind these materials into fine particles small enough (<4 μm) to reach the deepest part of the lung.
Microscopic Particles
Clearly, silica is an extremely common element. It is important to be aware of materials and products that contain silica, because when it is broken down, the particles become so small they can be inhaled into the lungs. These inhaled particles are highly dangerous, and can cause lung cancer, silicosis, difficulty breathing, and chronic obstructive pulmonary disease (COPD). The broken-down particles are microscopic; thus you are not aware when or even how much you are being exposed to. Respirable crystalline silica is a known carcinogen.
What Is Silica Dust: A Danger To Construction Workers
Of the 2.3 million workers that are exposed to silica in the US, the construction industry has the greatest exposure by far, with 2 million workers being exposed to this hazard. While silica is not a danger when the particles are larger, exercise caution when working with these materials. There are a variety of different dust-producing activities performed on construction sites that can cause significant respiratory damage to those exposed. All of these activities produce respirable silica dust; even small exposures cause damage to the lungs, eventually leading to the diseases discussed earlier. It is pertinent that the amount of respirable silica dust be controlled, as to minimize worker exposure, thus heightening safety in the workplace.