Summary
Highlights
To effectively fight fires, it's crucial to understand the fire triangle, which consists of oxygen, heat, and fuel. Fire extinguishers work by removing one of these elements. Using the wrong extinguisher, such as water on an oil fire, can worsen the situation. Different extinguishers are designed for specific fuel types; for instance, powder extinguishers suffocate fires by removing oxygen, while water extinguishers remove heat.
There are five main classes of fire extinguishers: Class A for ordinary combustibles (wood, paper), Class B for flammable liquids (oil, gas), Class C for energized electrical equipment, Class D for combustible metals (sodium, magnesium), and Class K for cooking oil fires (kitchens). Many extinguishers, like the common ABC type, can handle multiple classes of fires using a dry powder to smother them.
Portable fire extinguishers are designed for fires in their incipient phase, which is soon after ignition and roughly the size of an office trashcan. Do not attempt to extinguish fires that have progressed to the growth phase, as they generate too much heat and grow rapidly. Most fire extinguishers only last about 30 seconds. Always prioritize your safety; never block your exit, and only fight a fire if you feel comfortable and safe doing so.
To use a fire extinguisher, remember the PASS method: Pull the pin, Aim the nozzle at the base of the flames, Squeeze the trigger, and Sweep from side to side at the base of the flames. After extinguishing, remain vigilant as the fire can reignite. Always ensure your fire extinguishers are the correct type for potential fuels, properly charged, and ready for use.