1. basic knowledge of combustion: when any substance burns, there is a process from unburned state to burning state. There are three necessary conditions in this process, namely, combustible, combustion-supporting substance and ignition source, which must interact with each other.

2. Combustion-supporting substances: all substances that can help and support the combustion of combustible substances, that is, substances that can undergo oxidation reaction with combustible substances, are called combustion-supporting substances 3. Ignition source: all energy sources that can cause combustion reaction between combustible substances and combustion-supporting substances are called ignition sources.

3. Combustible: Any substance that can chemically react with oxygen or other oxidants in the air is called combustible.

4. How to use the carbon dioxide fire extinguisher: When putting out the fire, just lift or carry the fire extinguisher to the fire site. When it is about 5 meters away from the combustible materials, put down the fire extinguisher, pull out the safety pin, and hold the handle at the root of the horn with one hand and the pressure handle of the switch valve with the other. For carbon dioxide fire extinguishers without spray hose, the horn should be pulled up 70~90 degrees.

5. Isolation method: isolate or remove the burning place or object from the surrounding combustible materials, and the combustion will stop due to the lack of combustible materials. In actual use, such as moving flammable, combustible and combustion-supporting articles near the fire source, moving the burning articles to a safe place; Close the valves of power supply, combustible gas and liquid pipelines to prevent and reduce combustible substances from entering the combustion zone; Demolition of flammable buildings near the burning fire, etc.