Understanding Classification of Fires

Fires are one of the most dangerous hazards that can happen in any place, at any time. While many people might think of fire as a single entity, there are different classes of fires, each with their own unique characteristics and requirements for putting them out. Using the wrong type of fire extinguisher on a fire could do more harm than good. In this article, we will explore the main classifications of fires and provide a comprehensive overview of each type.

What are the Different Types of Fires?

Fires are classified based on the type of fuel that is burning, as well as the conditions under which the fire is burning. The five main classifications of fires are Class A, Class B, Class C, Class D, and Class K fires. Each of these classifications requires a different approach for extinguishing the fire, as well as a different type of fire extinguisher.

What is a Class A Fire?

A Class A fire is a fire that is fueled by ordinary combustibles such as wood, paper, cloth, or plastics. These types of fires are the most common and can be found in homes, offices, and other buildings.

Class A fires are characterized by a steady flame and the presence of ash and smoke. The flames can range from small and contained to large and spread rapidly.

These can be caused by a variety of factors, including faulty wiring, smoking materials, cooking accidents, and heating equipment. Class A fires can also be caused by natural disasters such as lightning strikes and wildfires.

How to Extinguish a Class A Fire

When extinguishing a class A fire, you’ll want to do it with water or a water-based extinguisher. For this type of fire, water possesses the ability to cool and extinguish flames, but if applied to other forms of fire, it may worsen the situation by spreading the flames or delivering an electric shock. Additionally, it is important to make sure that all the flames are completely extinguished to prevent the fire from reigniting.

What is a Class B Fire?

A Class B fire is a type of fire that is fueled by flammable liquids or gases, such as gasoline, oil, or propane. These types of fires are often found in industrial settings and can be extremely dangerous.

Class B fires are characterized by a fast-spreading flame and the potential for explosions. These fires can be difficult to extinguish, as the fuel source can continue to reignite the flames even after they have been put out.

Class B fires are often caused by improper storage of flammable materials, flammable liquids or gases, as well as malfunctioning equipment such as boilers, BBQ grill, or furnaces.

How to Extinguish a Class B Fire

When dealing with class B fires, it is crucial to avoid using water as the fuel involved may cause the flames to spread, resulting in more harm than good. Instead, the best approach is to decrease the oxygen supply and suffocate the flames. Foam is a popular choice in this situation.

For stovetop fires in the kitchen, sodium bicarbonate (baking soda) or potassium carbonate are effective in suffocating the flames. It Is recommended to keep a fire extinguisher in the kitchen that is classified for this class of fires.

What is a Class C Fire?

A Class C fire is a fire that is fueled by electrical equipment such as appliances, wiring, and circuit breakers. These types of fires are common in industrial and commercial settings where electrical equipment is used.

Class C fires are characterized by a burning smell, sparks or arcing, and the presence of flames near electrical equipment. They can also produce toxic smoke and gases.

Type C fires can be caused by faulty wiring, overloaded circuits, and malfunctioning electrical equipment. They can also be caused by human error, such as using electrical equipment improperly or failing to maintain it properly.

How to Extinguish a Class C Fire

Class C fires require a specialized extinguisher called a Class C extinguisher. These extinguishers use non-conductive extinguishing agents that are safe to use on electrical equipment. Water should never be used on Class C fires, as it can conduct electricity and create a dangerous situation such as electric shock.

What is a Class D Fire?

Class D fires are commonly found in chemical laboratories. This type of fire is fueled by flammable metals such as magnesium, titanium, and potassium. These class of fires are common in industrial settings where these metals are used.

Class D fires are characterized by a bright, intense flame and the release of toxic gases. They can also produce explosive reactions when exposed to water.

Common causes of this type of fire include mishandling or improper storage of flammable metals. They can also be caused by industrial accidents such as spills or explosions.

How to Extinguish a Class D Fire

This special type of fire requires a specialized extinguisher called a Class D extinguisher. These extinguishers use dry powders or sand to smother the fire and prevent it from spreading. Water should never be used on Class D fires, as it can react explosively with the metal and create a dangerous situation.

What is a Class K Fire?

Class K fires can be sparked by the ignition of cooking liquid such as grease, oil, animal fat or vegetable fat. Distinct from other forms of liquid fire, these blazes are exclusively generated in a kitchen setting and typically found in restaurants and food service businesses. However, any kitchen may become vulnerable to class k fires – so take proper precautions!

These fires are characterized by the presence of burning liquid, which can spread quickly and dangerously. As a result, these fires require immediate action to contain and extinguish.

Class k fires are commonly caused by cooking liquid ignitions – when the temperature of a high-volatility fat, oil or grease source is raised too quickly or exposed to an open flame. Unattended cooking is particularly dangerous in this respect, as these fires can quickly become out of control.

How to Extinguish a Class K Fire

Saponification, the process in which triglycerides are combined with a strong base to form fatty acid metal salts during the soap-making process, is by far the most efficient and reliable method of combating class K fires. Fire extinguishers that are designed for class k contain a wet chemical agent which, when dispensed on the cooking oil or fat serving as fuel, converts it into soap – thus putting out the blaze.