Employers must reduce exposure to crystalline silica below the permissible exposure limit (PEL) of 50 micrograms per cubic meter of air averaged over an 8-hour work shift. High-risk activities include cutting or grinding concrete, drilling or chipping masonry, grinding mortar or stone, and sandblasting with silica. Engineering controls must be the primary method of reducing exposure. Water spray systems during concrete cutting and grinding suppress dust and reduce airborne silica. Local exhaust ventilation on grinders and other equipment removes dust at the source. Enclosures can contain dust from high-intensity operations. Wet sweeping instead of dry sweeping prevents resuspension of silica dust. Substituting other materials like limestone for silica-containing sand reduces hazards. Personal protective equipment must be used when engineering controls cannot reduce exposure adequately. Respirators must be selected based on job specific hazard assessment. NIOSH-approved respirators must be used and fit testing must be performed before use. Medical surveillance must include baseline and annual chest X-rays and spirometry tests for workers with potential exposure. Periodic medical exams must be provided for 30 years after last exposure. Employees must be informed of silica hazards and provided training on prevention measures. Recordkeeping must track exposure monitoring and medical surveillance results.