Chemical hazards can arise from substances that are toxic, corrosive, flammable or explosive if inhaled, swallowed, or absorbed through the skin. The document discusses the definition of chemical hazards and various sources such as household cleaners, industrial chemicals, and gases. It also outlines the four main routes chemicals can enter the body (ingestion, inhalation, absorption, injection) and common health effects like skin/eye irritation, asthma, poisoning and cancer. Guidelines are provided for safely handling, storing and disposing of chemicals in various settings like laboratories, food production facilities and mines. Hazard symbols are described which indicate the types of risks different chemicals pose.