二氧化碳灭火剂是一种具有一百多年历史的灭火剂，价格低廉，获取、制备容易，其主要依靠窒息作用和部分冷却作用灭火。二氧化碳具有较高的密度，约为空气的1.5倍。在常压下，液态的二氧化碳会立即汽化，一般1kg的液态二氧化碳可产生约0.5立方米的气体。因而，灭火时，二氧化碳气体可以排除空气而包围在燃烧物体的表面或分布于较密闭的空间中，降低可燃物周围或防护空间内的氧浓度，产生窒息作用而灭火。另外，二氧化碳从储存容器中喷出时，会由液体迅速汽化成气体，而从周围吸引部分热量，起到冷却的作用。

Carbon dioxide fire extinguishing agent is a kind of fire extinguishing agent with a history of more than one hundred years, the price is low, access, easy preparation, which rely on smothering action and part of its cooling effect. Carbon dioxide has a high density, about 1.5 times as much as air. Under normal pressure, liquid carbon dioxide vaporizes immediately, and a typical 1kg of liquid carbon dioxide produces about 0.5 cubic meters of gas. Thus, fire, carbon dioxide gas can eliminate air and surrounded on the distribution of the burning surface of the object or in a confined space, reduce the concentration of oxygen in the fuel or protective space around, smothering action and put out the fire. In addition, when carbon dioxide is ejected from the storage vessel, it will be vaporized quickly by the liquid, which will absorb some of the heat from the surrounding area and act as a cooling. 

二氧化碳灭火器主要用于扑救贵重设备、档案资料、仪器仪表、600伏以下电气设备及油类的初起火灾。在使用时，应首先将灭火器提到起火地点，放下灭火器，拔出保险销，一只手握住喇叭筒根部的手柄，另一只手紧握启闭阀的压把。对没有喷射软管的二氧化碳灭火器，应把喇叭筒往上扳70—90度。使用时，不能直接用手抓住喇叭筒外壁或金属连接管，防止手被冻伤。在使用二氧化碳灭火器时，在室外使用的，应选择上风方向喷射；在室内窄小空间使用的，灭火后操作者应迅速离开，以防窒息。

Carbon dioxide fire extinguishers are mainly used to save valuable equipment, file data, instrument meters, 600 volts of electrical equipment and the initial fire of oil. When use, should first will be a fire extinguisher mentioned locations, put down the fire extinguisher, pull out the latch, one hand hold the megaphone root handle, another hand hold the opening and closing valve pressure. For a carbon dioxide extinguisher that does not have a hose, the bell-tube should be turned 70 to 90 degrees. When used, you can't use your hands directly to hold the outer wall or metal connection pipe to prevent frostbite. When using a carbon dioxide extinguisher, it should be used outside, and should be ejected in the upper direction. In a small room in a small room, the operator should leave immediately, in case of suffocation.