Hazardous areas are locations where there is a risk of fire or explosion due to the presence of flammable gases, vapors, or dust. These areas are classified based on the likelihood and duration of the hazardous conditions. Common examples include oil refineries, chemical plants, and grain storage facilities. To ensure safety, hazardous areas are divided into zones, such as Zone 0, Zone 1, and Zone 2 for gases, and Zone 20, Zone 21, and Zone 22 for dust. Proper equipment and safety measures are essential in these areas to prevent accidents and protect workers.