1926.1153: Respirable crystalline silica. PEL: 50 µg/m³ (8-hr TWA). Action level: 25 µg/m³. Silica sources in construction: cutting/grinding concrete, masonry, stone, mortar; drilling rock/concrete; demolition; abrasive blasting. Table 1 — specified exposure control methods for 18 tasks: Stationary masonry saw = continuous water feed + water supply 0.5 gal/min. Handheld power saw = continuous water feed or dust collector vacuum + HEPA filter. Jackhammer = continuous water flow or dust collector. Concrete grinding = vacuum dust collection + HEPA filter. Core drilling = continuous water feed. Employers can follow Table 1 (no monitoring required if controls used) or measure actual exposure and implement controls. Medical surveillance: initial + every 3 years for workers above action level for 30+ days/year. Written exposure control plan required. Housekeeping: no dry sweeping/compressed air; vacuum with HEPA or wet methods. Recordkeeping: air monitoring, medical surveillance.