How can respirable crystalline silica exposures be controlled to keep exposure at or below the permissible exposure limit or PEL?

Employers must use engineering controls and work practices as the primary way keep exposures at or below the PEL.

• Engineering controls include wetting down work operations or using local exhaust ventilation (such as vacuums) to keep silica-containing dust out of the air and out of workers’ lungs. Another control method that may work well is enclosing an operation (“process isolation”).
• Examples of work practices to control silica exposures include wetting down dust before sweeping it up or using the water flow rate recommended by the manufacturer for a tool with water controls.
• Respirators are only allowed when engineering and work practice controls cannot maintain exposures at or below the PEL.

For construction, the standard includes Table 1, a list of common construction tasks along with exposure control methods and work practices that work well for those tasks and can be used to comply with the requirements of the standard.