Classes Of Fire: Importance & Prevention

Classification of a fire is just as important as learning how to stop it. In fact, both of them go hand in hand. Proper knowledge of the fire can help you quickly resolve the issue. 

Fires can originate from a number of different reasons and hence classifying them based on origin is essential. In this way, we can try to control the fire with a methodical approach. 

So what are the classes of fire and how exactly do they differ. That’s exactly what we’re going to try to find out today.

 There are a total of 5 classes of fire, namely class A, Class B, Class C, Class D, and Class K. each of thee classes differentiate from one another on the basis of their intensity, point of origin, and method of putting them out 

Knowing when to put out the fire can be just as important as learning the components that constitute the fire so for a much better grasp on the topic of fire check out his article on the stages of fire.

Class A:


The most basic of all classes and the one which is the lowest in terms of the total intensity and ferocity. Class A fires are composed of easily combustible materials. This class of fire can be lit by intentional means and can be easily controlled. Let’s go through some examples, burning of paper, wood even trash can all be considered a class A materials. 

So how can you put out a fire of this type, well due to its basic composition a simple fire extinguisher or even water can do you just fine. Here smoke detectors can comes in really handy, proper positioning is essential of the detector so be sure to check out our guide on exactly that.

These types of fires can easily be prevented and controlled, but as with any fire if left unsupervised it can grow quite rapidly and cause a lot of destruction. So when dealing with fire even of this magnitude be extra careful. And always remember that at any point if you think that the fire is growing immediately contact the local fire department.

Class B:

 

These types of fires are composed of combustible liquids or gasses. These are much more dangerous than the previous class as they can spread quite rapidly. They also need more time and effort to be controlled.

In most cases, water cannot be used so the best thing that you can use in a situation like this is a fire extinguisher. Most people assume that kitchen house fires or greasy fires are class B fires but that is not the case. Due to the immense variety of material in kitchen fires, they have a separate class known as the class K.

Gasoline, petroleum-based products, other flammable liquids, and gases of the same type are included in this category. 

Class C:


Class C fires constitute electrical fires. These in many ways are the most difficult fires to control. As one can expect, water can not be used in such a situation, you would require a dry powdered fire extinguisher since foam-based fire extinguishers can also be electrically conductive.

These types of fires are quite common in industries and even in homes, in fact, they are one of the most common causes of house fires. All electronic devices are prone to malfunction under specific conditions.

Fridges, televisions, computers switch ports can all short circuit and this can cause an electrical fire to start. If an accident of this type occurs then the best plan of action would be to disconnect the power supply, you can either unplug the switch or switch off the main power supply.

Class D:


This class consists of combustible materials such as titanium and potassium. Mostly used in industries, these metals can easily be ignited and can be really hard to control. Since these types of fires originate from alkali metals they are most commonly found in industries and Laboratories. 

Alkali metals are easily combustible and can produce a highly exothermic reaction. The fires that originate from these sources can only be controlled in a specific manner. With the help of dry powdered agents, these fires can be controlled, but still can be very dangerous.

Class K:


As the name suggests, class K fires deal with kitchen fires. The frequency and the variability in the fuel are what warrants a separate class for these types of fires.

Sometimes class K fires are called grease fires, named because of the use of grease as a fuel. These types of fires can’t be put out with the use of water, since water and hot oil can actually cause the fire to become more intense.

To eradicate such types of fires quickly you must stop the fuel supply. Covering the fire with a lid is actually a quick and easy way to stop the fire. By doing so the oxygen supply is depleted and the fire eventually dies out.

Differences in classes of fires depending on the region:

If you’ve searched this topic before then you’ll realize that the classes of fire actually vary a lot. Some websites state that natural gas fires are included in class B whereas others don’t agree at all and classify them as a separate class altogether.

These differences are because of the fact that different geographical areas classify fires according to their own standards, they are quite similar but differences do exist. So let’s take a brief overview of the classes of fire and their geographical variations.

European standards:

According to the European standards, fires are classified as A, B, C, D, and F. they are all quite similar to the ones we’ve discussed above just with some slight change.

  • Class A deals with combustible materials such as wood
  • Class B deals with flammable liquids
  • Flammable gases on the other hand are included in Class C
  • Flammable metals are included in class D
  • Kitchen fires or grease fires are included in class F
  • Electrical fires are not included in the classification system

American standards:


In the above-mentioned classes, we followed the American standards, so here a quick overview of the classes of fire according to the American standards

  • Class A is basically the same as it includes combustible materials
  • As far as Class B is concerned it is a little bit more diverse since it includes both flammable gases and liquids
  • Class C includes electrical fires
  • Class D is the same in all three regions meaning that all of them are related to flammable metals
  • As we’ve described above Class K is related to kitchen fires

Australian standards:


The Australian classification system is pretty easy to understand, it includes the following classes of fire A, B, C, D, E, and F. As you may notice this classification system is almost identical to the European version with the exception of electrical fires.

  • Class A is the same as the other classes
  • B class includes flammable liquids
  • Flammable gasses are included in Class C
  • Class D includes combustible metals
  • Class E deals with electrical fires
  • Lastly, class F is for kitchen or grease fires

FAQs:


Q1) What type of fire can be put out safely with water?

As we’ve discussed in detail, Class A fires are the ones that can be safely put out by water. The origin of the fire dictates whether water can be used or not so if its combustible material such as wood then water can be used.

Q2) How to put out a fire without a fire extinguisher?

Depeding on the Class of fire a number of ways can be employed to ensure that the fire does not spread, without the use of a fire extinguisher. For example in class A fires water can be used, in Class K fires you can put a lid on top of the pot to cut off the fuel supply and extinguish the fire. It is however best that you keep a fire extinguisher with you at all times.

Q3) What do you use on chemical fires?

Usually dry powedred agents can be employed but this also dpedns on the type of chemicals onfire.

CONCLUSION:

Hope this guide helped you in learning the different classes of fires, what they mean, and the differences that can occur based on the geographical variations. In all cases of fire remember to always contact the emergency services if you even get the slightest hint that the fire is expanding. You can find more helpful articles like this over at firefightertools.co.

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