Primary Sources of Silica Exposure

Silica dust is generated during the hydraulic fracturing process in various ways. According to NIOSH, the seven primary sources of silica dust that expose workers to the greatest risk of silica exposure are as follows:

• Silica dust that escapes from access ports (thief hatches) on top of the vehicles that move sand during sand refilling operations while the machines are running (known as hot loading)
• Silica dust that escapes through open fill ports on the sides of the sand movers during refilling operations
• Silica dust that is kicked up by vehicles moving around the site
• Silica dust that escapes from the transfer belt underneath the sand movers
• Silica dust that is generated when sand is agitated, or when sand is dropped into the blender hopper or placed on transfer belts
• Silica dust that escapes during the movement of sand on transfer belts between the sand mover and the blender
• Silica dust that escapes from the top end of the sand transfer belt (dragon's tail) on sand movers

The dust released from sand in these various ways hangs suspended in the air that surrounds workers on oil and gas extraction sites. These clouds of dust expose workers to unsafe levels of silica.

To learn more about Oil & Gas Extraction visit our Oil & Gas Extraction Safety Online Training web page.