To remain compliant, you must use engineering controls to keep employee's silica exposure below 50 µg/m3 when they use masonry saws and other cutting equipment. These controls include wet methods and improving ventilation in the area.
Wet methods keep the cutting or grinding surface moist to prevent silica from becoming airborne. Proper ventilation is another way to protect workers as it keeps air moving and prevents them from inhaling airborne silica.
If you cannot practically implement engineering controls, having workers wear respirators is another option. However, your workers must each have a properly fitting mask that they wear throughout their shift. Also, using respirators may impair workers because these protective devices may block the worker's view or ability to hear.
In some instances, OSHA requires the use of respirators even with engineering controls. For example, if using a walk-behind saw indoors, your worker must wear a respirator with an assigned protection factor of 10. The same requirement holds if using a power saw inside for any length of time or outdoors for more than four hours. Concrete dowel drilling rig operators must also use respirators for the use of the machinery anywhere for any amount of time.