These days, fire extinguishers aren't just useful to have around in a building; they are a legal requirement. But not all fire extinguishers are made equal. That's not to say that one type is better than another — it's just that certain buildings and materials pose different kinds of fire risks. Many people are aware that there are a few different fire types, but there is only a very small percentage of people who can name all of the types and what they are useful for.
All in all, there are nine different types of fire extinguishers, and they all have unique benefits in specific situations. The different kinds are as follows:
- water
- foam
- dry chemical
- wet chemical
- carbon dioxide
- clean agent
- water mist
- cartridge-operated dry chemical
- dry powder
Naturally, it is cost prohibitive and impractical to have all nine on standby, so this article will strive to highlight where a few of these extinguishers are best used.
The first thing to note is that fires are divided into four separate classes: A, B, C, and D.
A Class A fire is one that involves common fuel sources such as paper, wood and cloth.
A Class B fire is one that involves combustible and flammable liquids and gases, and it also includes paints and gasoline.
A Class C fire is one that involves electrical equipment, especially where a short circuit, faulty wiring or other malfunction has occurred.
A Class D fire is one that involves flammable metals such as potassium, lithium and sodium.
Let's look at some typical uses for a few of the most commonly used extinguishers. A foam extinguisher, for example, works well with Class A and Class B fires, but it should never be used on a Class C fire, as doing so can cause an electric shock. On the other hand, a dry chemical extinguisher is suitable for Class A, B, and C, making it the most commonly used fire extinguisher and one of the most versatile as well.
As most people know, there is something called a combustion triangle — also known as a fire triangle — which is the name given to the three things needed for a fire: heat, fuel, and an oxidising agent. A dry powder extinguisher splits the fuel from the oxygen, or eliminates the heat element of a fire. What makes a dry powder extinguisher particularly useful is that is it can be used on Class D fires; however, it only works on this class of fire.
