Classes of Fires and Types of Fire Extinguishers

Did you know there are different classes and types of fire extinguishers? I am going to write about two important topics for someone who loves being outdoors. On the one hand, I am happy to share what we know about the different types of fires and how to put them out safely. On the other hand, I want you to be aware of some everyday safety measures that will help prevent a fire from happening in the first place.

In order to do this, let’s begin by defining what a fire is and where it gets its energy from— because understanding these things helps us identify stages in which we can take action or remove fuel sources that would otherwise contribute or continue getting energy into a fire. First, there is combustion: when materials react with oxygen in an exothermic reaction and release energy to their surroundings in the form of light and heat. [e.g. your stovetop, campfire, etc.]. Second, there is fire suppression: the opposite of combustion. This process involves removing oxygen from the surrounding environment and cooling materials outside of the fire.

Classes of Fires

We can also classify fires into four main categories based on where they are burning and what they are made of. Let’s take a look at each one.

Classes of Fires

Class A
A Class A fire is the presence of ordinary solids such as paper, wood, cloth and some plastics. This kind of fire burns clean, meaning it doesn’t produce a lot of smoke.

Class B
This type of fire is made up of both combustible liquids such as liquid petroleum and flammable gases like propane, butane and ether. In the case of flammable gases, the solids in this type of fire are able to be ignited higher up compared to solid materials that burn lower to the ground. Learn about Is Oil Flammable

Class C
A Class C fire is a type of fire that happens in Electrical equipment, appliances and wiring. This type of fire can be prevented with the use of a non-conductive extinguishing agent. Do NOT use WATER on a Type C Fire!

Class D
A class D fire is usually not seen outside of medical facilities. It is made up of combustible / flammable metals such as sodium, magnesium, titanium and liquid chlorine.

Must Read: Top Fire Protection Tips for Your Home

Factors that Affect a Fire’s Ability to Burn

Factors that affect a fire’s ability to burn is its fuel source, oxygen supply and heat. When these things are not in place, the fire will remain extinguished until they are present again.

Fuel Source: fuel is necessary for a fire. If there is no fuel, the fire cannot continue burning. A lack of fuel would extinguish a fire just as much as removing oxygen or cooling the surrounding environment. Fuel can be anything from paper or wood to gasoline or propane tanks.

Oxygen Supply: All fires need oxygen in order to maintain themselves and to keep burning. If you remove or reduce the amount of oxygen present, the fire will go out since it cannot obtain enough oxygen to stay alive.

Heat: The heat of a fire is important in maintaining the fire and keeping it burning. If the fire itself is not warmed up enough, it will go out since it cannot withstand its own temperature which is usually higher than that of its surrounding environment.

Keep these factors in mind in order to make sure a fire is properly managed and put down to prevent any damage or harm to yourself or property.

Types of Portable Fire Extinguishers:

In addition to classes of fires, we can also identify different types of extinguishers. Fire extinguishers are classified as types A, ABC, BC or K. It is important to identify the right type of extinguisher for the fire burning. If the wrong type of fire extinguisher is used, it may cause electrical shock or spread the fire. 

Below we have listed each type of extinguisher and what type of fire it should be used for.

Note: Portable extinguisher work well for small fires. If a fire is large and has already spread, it is best to keep doors closed to contain the fire and call the fire department.

Type A Extinguishers: These fire extinguishers are intended for fires of ordinary combustible materials such as paper and wood. These water extinguishers are effective at putting out Class B or C fires; in fact they may cause the fire to spread. These extinguishers will put out any flames but won’t put out a fire once it has started without additional means of causing an extinction wave.

Type ABC Extinguishers: A type ABC will be effective against all fires including electrical fires. It uses a dry chemical to suppress the fire.

Type BC extinguishers: This type of fire extinguisher should be used on class B fires. BC extinguishers are also effective at putting out class C fires and are carbon dioxide  based.

Type K Extinguishers: These are intended for combustible cooking oils and electrical equipment such as small appliances, motors or wires. These are most commonly used to put out cooking fires in home and commercial kitchens due to fires from cooking oils or grease fires.

Learn more about fire safety: Fire Protection vs Fire Prevention

How to Use a Fire Extinguisher

A simple and effective way to remember how to use an extinguisher in case of emergency is the P.A.S.S. system.

P = Pull the extinguisher pin
A = Aim at the base of the fire with the nozzle
S = Squeeze the extinguisher’s trigger to release the fire suppression product
S = Sweep from side to side with the nozzle in a slow, steady motion

Conclusion for Classes of Fires and Types of Fire Extinguishers

We hope this article helps you understand the classes of fires along with what type of extinguisher is best used to suppress each type. I will leave you with one more important note. It is critical to remain calm and plan your course of action during a fire. 

If you have questions or need additional recommendations in regards to Classes of Fires and Types of Fire Extinguishers please leave a comment below.

FAQ

What are the different classes of fires?

The three most common classes of fires are Class A (regular combustible materials), Class B (combustible liquids) and Class C (electrical fires). There are also Class D (combustible metals usually seen in medical facilities). In addition some countries classify Cooking oils as Class F(EU/AU) or a separate Class K (US).

What are the different types of portable fire extinguishers?

Portable fire extinguishers come in 4 types, Type A (water based), Type ABC (dry chemical based), Type BC (carbon dioxide) and Type K (for grease fires).

What are items that may be included in a monthly inspection?

A monthly inspection includes an a physical examination to determine if any physical damage, corrosion or leakage can be seen. In addition, a reminder to anyone in the residence should be given of the location of the fire extinguishers. A through yearly inspection should be completed by a trained professional.

How do I use Portable Fire Extinguishers?

A simple and effective way to remember how to use an extinguisher in case of emergency is the P.A.S.S. system.

P = Pull the extinguisher pin
A = Aim at the base of the fire with the nozzle
S = Squeeze the extinguisher’s trigger to release the fire suppression product
S = Sweep from side to side with the nozzle in a slow, steady motion

How long do extinguishers last?

Dry chemical fire extinguishers usually contain water mixed with some kind of powdery substance. As they age, these chemicals may eventually lose their ability to hold a charge. In addition, because these devices use pressurized carbon dioxide cartridges, they tend to leak after extended periods of nonuse. 

To find out how long your unit lasts, look at the expiration date on the label. Models usually last between 5 and 15 years. With some models, you can get professional recharge kits for them so they last longer.

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