Which chemical agent is used in a Type ABC fire extinguisher for fire suppression?

A Type ABC fire extinguisher is specifically designed to combat fires that fall into three categories: Class A (ordinary combustibles), Class B (flammable liquids), and Class C (electrical fires). The chemical agent primarily used in these extinguishers is a dry chemical retardant, usually composed of monoammonium phosphate.

This dry chemical is effective because it works by interrupting the chemical reaction of the fire. It can provide a blanket over the burning material, cutting off the oxygen supply and helping to suppress the flames. Its versatility makes it suitable for a wide range of fire types, which is why it is the preferred agent in Type ABC extinguishers.

In contrast, water is effective for Class A fires but can be dangerous for Class B and C fires due to the potential for spreading flammable liquids and conducting electricity. Foam extinguishers are designed mainly for flammable liquid fires (Class B) and are not effective on electrical fires. Carbon dioxide extinguishers are beneficial for Class B and C fires but do not have the effectiveness against Class A fires that a dry chemical can provide. Therefore, the use of a dry chemical retardant in a Type ABC fire extinguisher is what makes it the superior choice for