This document discusses occupational health hazards, specifically chemical hazards. It defines occupational health as recognizing, evaluating, and controlling workplace hazards that can cause illness. It then discusses the main types of chemical hazards: dusts, fumes, mists, fibers, gases, and vapors. For each hazard type, it provides examples of chemicals that fall into that category. It also discusses acute and chronic health effects of chemical exposures. Threshold limit values and time-weighted average concentrations are defined as metrics for safe chemical exposure levels. Specific health and safety information is then provided for sulfuric acid and sodium hydroxide, two common industrial chemicals.