Full definition
Fine particles (PM10 and PM2.5) generated during loading, transport, and discharge of bulk materials that remain suspended in the air. In mining, crystalline silica dust causes silicosis, an irreversible pneumoconiosis. Occupational exposure limits: OSHA PEL 0.05 mg/m³ for respirable crystalline silica. Control measures: water or foam suppression, local exhaust ventilation hoods, sealed transfer points. Reference standards: ISO 14405, NOM-010-STPS (Mexico), DS 594 (Chile).