Fire extinguishers are a common and important firefighting equipment, widely used in homes, offices, schools, factories, and other places.

Its main function is to extinguish the initial fire and prevent the fire from spreading, thereby protecting life and property.

Although the design and appearance of fire extinguishers vary in different types and uses, their core principles and operation methods are relatively simple. Knowing how to use fire extinguishers correctly and choosing the right type of fire extinguisher is essential for everyone.

The working principle of fire extinguishers is based on suppressing one of the four elements of fire, namely combustibles, heat, oxygen, and chemical chain reactions.

When using a fire extinguisher, the flame is extinguished by spraying extinguishing agents to cut off one or more factors that the fire depends on. Different types of fire extinguishers use different extinguishing agents, so their applicability in different fire scenarios is also different.

Water-based fire extinguishers are the most common type and are suitable for extinguishing Class A fires, that is, fires of solid materials such as wood, paper, and fabrics. Water-based fire extinguishers work by spraying water to cool the burning material, lowering the temperature, and extinguishing the flame.

However, water-based fire extinguishers are not suitable for electrical equipment fires or grease fires because water and electricity conduct electricity, which increases the risk of electric shock.

Foam fire extinguishers work in a similar way to water-based fire extinguishers, but in addition to cooling the burning material, they can also form a layer of isolation film through foam to block the contact between the burning material and oxygen in the air.

Therefore, foam fire extinguishers are not only suitable for extinguishing Class A fires but also effectively deal with Class B fires, that is, liquid fires such as oils and chemical solvents.

The versatility of foam fire extinguishers makes them the first choice in many places. However, like water-based fire extinguishers, foam fire extinguishers are not safe when dealing with electrical equipment fires.

Dry powder fire extinguishers are a more universal fire extinguishing equipment that is suitable for extinguishing Class A, Class B, and Class C fires. Class C fires are gas fires, such as natural gas, propane, and acetylene fires.

The extinguishing agent of a dry powder fire extinguisher is a fine powder, usually a chemical substance such as ammonium phosphate or sodium bicarbonate.

Its working principle is to destroy the chemical chain reaction of the fire through chemical reactions while covering the surface of the burning object to prevent the flame from contact with oxygen.

The advantage of dry powder fire extinguishers is that they have a wide range of applications, but they also have certain disadvantages, especially that a large amount of dust will be left after use, which is difficult to clean up, and in some occasions with precision equipment, the use of dry powder fire extinguishers may cause damage to the equipment.

Carbon dioxide fire extinguishers are mainly used to extinguish Class B fires and electrical equipment fires. Carbon dioxide is a non-toxic gas that is liquefied and stored in a fire extinguisher under high pressure. When used, carbon dioxide expands rapidly and turns into gas, which can effectively reduce the oxygen concentration around the burning object and cool the burning object to achieve the purpose of extinguishing the fire.

The biggest advantage of carbon dioxide fire extinguishers is that they leave no residue after use and will not pollute the equipment or the environment. Therefore, they are particularly common in sensitive places such as computer rooms and laboratories. However, carbon dioxide fire extinguishers are less effective in open spaces because the gas is easy to spread and it may cause suffocation at high concentrations. Special attention should be paid to safety when using them.

In the face of large-scale fires or rapidly spreading fires, it is the wisest choice to evacuate in time and seek help from professional firefighters. Therefore, the use of fire extinguishers is as important as the popularization of daily fire protection knowledge.

Learning how to use a fire extinguisher correctly, understanding its maintenance methods, and conducting regular fire drills can effectively improve individual and collective fire response capabilities!