In February 2015, OSHA and the National Institute for Occupational Safety and Health (NIOSH) published the Hazard Alert on Worker Exposure to Silica during Countertop Manufacturing, Finishing and Installation (Hazard Alert).1

According to the Hazard Alert, in the stone countertop industry, workers can be exposed to airborne silica dust during the cutting, grinding, chipping, sanding, drilling, and polishing of both natural and manufactured stone products or when working with ground quartz. The Hazard Alert identifies a number of measures employers can implement to protect workers from overexposure to silica in this industry. First, it is recommended that employers conduct employee air monitoring to determine which jobs expose workers above exposure limits. If sampling reveals exposure above the OSHA Permissible Exposure Limit (PEL), employers are required to take action to reduce worker exposures to below the PEL. Additionally, employers are encouraged to take these actions even if air monitoring does not reveal exposure above the PEL. 

The Hazard Alert also lists a variety of engineering controls and safe work practices that should be implemented to protect workers, including: various water spraying systems, ventilation controls, and other wet methods to help control dust; isolation of dust-generating operations using enclosures, walls, or control booths; and performance of work under controlled conditions and minimization of work at the point of installation. When engineering controls and work practices do not limit silica exposure to the PEL, employers must provide workers with respirators (NIOSH-approved N95 respirator or greater). In addition, employers are encouraged to consider medical monitoring for workers exposed to silica at or above one-half the PEL.