Many workers, especially construction workers, are exposed to crystalline silica.  Workers are at risk for silicosis, lung cancer, chronic obstructive pulmonary disease (COPD), and kidney disease when they inhale very small crystalline silica particles.  Engineering controls are commonly used to control silica dust.  On September 12, 2013 OSHA released a notice of proposed ulemaking (NPRM) for occupational exposure to respirable crystalline silica (available here). Learn more about the health effects, uses and properties of crystalline silica in this report released by the National Toxicology Program by clicking here.  This information is especially relevant to Construction Outreach trainers.