Fire extinguishers are divided into dry powder extinguishers, foam extinguishers and carbon dioxide extinguishers. Dry powder fire extinguishers are commonly used. When using them, you should first shake the bottle back and forth to loosen the dry powder inside, and then pull out the lead seal and safety plug. The posture is to hold the nozzle with your left hand and hold the handle with your right hand. Then, at a distance of about two meters from the fire, press the handle with your right hand and spray dry powder back and forth with your left hand holding the nozzle. When using a foam extinguisher, you should stand upwind and slightly close to the fire source. Its spraying distance is about 2-3 meters, so you should start spraying from the place where the fire is strong, and then move slowly. Hold the wooden handle of the nozzle to avoid being frostbitten by cold air. After putting out a fire, you should open a window in time to ventilate and exhaust carbon dioxide in the air. Generally, there are two types of carbon dioxide fire extinguishers, switch type and knife type. When using, you should hold the wooden handle with one hand, press the switch with the other hand, and then lift the bottle up. In addition, the knife type fire extinguisher cannot be closed after being opened, and it is best to use it all at once.