What is Class A vs B vs C fires

Fires are classified based on the type of fuel involved and the appropriate extinguishing method. Class A, B, and C fires are three commonly used classifications that help firefighters and individuals understand the nature of a fire in order to respond effectively. Each class has its unique characteristics and methods of suppression. In this article, we will explore what Class A, B, and C fires are, their differences, and how they can be extinguished.

Class A Fires: Combustible Materials

Class A fires involve common combustible materials such as wood, paper, cloth, and plastics. These fires are characterized by the glowing embers and the formation of hot ashes. They spread through direct contact with a burning surface, which means that once the initial source catches fire, the flames steadily progress to ignite other nearby materials. To combat Class A fires, water or water-based extinguishers are typically effective. The water cools down the fire and extinguishes it by depleting the heat necessary for combustion.

Class B Fires: Flammable Liquids and Gases

Class B fires are fueled by flammable liquids and gases, including gasoline, oil, propane, and alcohol. Unlike Class A fires, these fires do not leave behind ashes and embers. Instead, they are characterized by rapidly spreading flames and intense heat. Due to the volatile nature of the fuels involved, water may not be suitable for extinguishing Class B fires as it can cause the fuel to spread further, making the situation more dangerous. Instead, foam or dry chemical extinguishers are commonly used to suppress Class B fires. These extinguishing agents create a barrier between the fuel and oxygen, smothering the fire and cutting off its ignition source.

Class C Fires: Electrical Equipment

Class C fires involve electrical equipment and wiring. The primary danger associated with these fires is not necessarily the fire itself but the potential for electric shock caused by the energized electrical components. In Class C fires, the electrical current acts as both the ignition source and the fuel. It is vital to de-energize the electrical equipment before attempting to extinguish the fire. CO2 (carbon dioxide) or dry chemical extinguishers are commonly used for Class C fires as they do not conduct electricity and can effectively smother the flames. These extinguishers remove the oxygen from the fire triangle, preventing further combustion.

In summary, understanding the differences between Class A, B, and C fires is crucial in selecting the appropriate firefighting tactics and extinguishing agents. While water is suitable for Class A fires, flammable liquids and gases require foam or dry chemical extinguishers, and electrical fires necessitate CO2 or dry chemical extinguishing methods. Being aware of the classification system and equipped with the right knowledge and tools empowers individuals to respond effectively and swiftly in case of a fire emergency.