The dry powder fire extinguisher is filled with ammonium phosphate dry powder fire extinguishing agent. Dry powder fire extinguishing agent is a dry and easily flowing fine powder used for fire extinguishing. It is composed of inorganic salt with fire extinguishing effect and a small amount of additives which are dried, crushed and mixed into fine solid powder. It is a fire extinguishing agent widely used in fire fighting, and is mainly used in fire extinguishers.

Ordinary dry powder extinguishing agent is mainly composed of active extinguishing component, hydrophobic component and inert filler. The hydrophobic component mainly includes silicone oil and hydrophobic white carbon black. There are many kinds of inert filler, which mainly play the role of anti vibration compaction, caking, improving the movement performance of dry powder, catalyzing the polymerization of dry powder silicone oil and improving the compatibility with foam extinguishing agent. This kind of common dry powder fire extinguishing agent has been widely used at home and abroad.