1. The minimum design concentration for extinguishing combustible liquid fires, fusible solid fires, flammable gas fires, flammable solid surface fires and electrical fires should be 37.5%;
2. The minimum design concentration of some flammable liquids can be determined according to Appendix B;
3. The maximum design concentration of the protected area where people are often working is 43%, and it should be checked under the expected maximum ambient temperature of the protected area.
4. When there are multiple combustibles, the design concentration of the extinguishing agent should be determined according to the design concentration of combustibles with a large number of combustibles and a high fire danger;
5. The inertization concentration shall be adopted for the protection area with explosion danger, which can be determined according to Appendix C.