Exposure to Silica Dust Assessments

Crystalline silica is a basic component of soil, sand, granite and many other minerals. Quartz is the most common form of crystalline silica. It may become respirable size particles when workers chip, cut, drill, or grind objects that contain crystalline silica.

Jobs that may put employee at risk of exposure to crystalline silica include blasting, foundry work, stonecutting, rock drilling, quarry work and tunneling. Breathing crystalline silica dust can cause silicosis which may be disabling or even fatal. The respirable silica dust enters the lungs and causes the formation of scar tissue, thus reducing the lung's ability to take oxygen.

There are three types of silicosis:

  • Chronic / classic silicosis which occurs after 15 - 20 years of moderate to low exposures to respirable crystalline silica, is the most common type of silicosis.
  • Acute silicosis which occurs after a few months or as long as 2 years following exposures to extremely high concentrations of respirable crystalline silica.

Measurement of employee exposure to silica is conducted using air filters housed in a filter cassettes, a cyclones as well as air sampling pumps.