Classes Of Fire Extinguishers

In this write-up, we will discuss the different classes of fire extinguisher, their associated icons, and the various types of extinguishers and their applications.

Not all fires are created equal, although they are categorized due to the type of fuel used. By using the incorrect types of fire extinguisher on the incorrect type of fire, you can actually make it worse. It is important to consider the distinct classes of fire extinguisher. Various kinds of fire extinguishers are available to combat various types of fire. Since there are several forms of explosions, there are numerous types of fire extinguishers. Each extinguisher is designed to combat specific types of fires, and it’s critical for you to understand the distinctions if your career requires you to fight fires on the job. Being able to tell which types of fire extinguisher you need in an emergency might mean the difference between life and death. Before we go ahead with the classes of fire extinguisher, let’s talk about what fire extinguisher is.

types of fire extinguishersA fire extinguisher is a compact or movable apparatus that is used to extinguish a small fire by guiding a fluid onto it that cools the burning fuel, deprives the blaze of oxygen, or interferes with the chemical reactions occurring in the flame. Water fulfills two of these functions: its conversion to steam consumes heat, and the steam displaces the surrounding air. As a result, often basic fire extinguishers are tiny tanks fitted with hand pumps or compressed gas sources that push water through a nozzle. Water can include a wetting agent to increase its effectiveness against upholstery burns, an additive to create stable foam that serves as an oxygen barrier, or antifreeze. Carbon dioxide is a natural propellant that is activated by withdrawing the locking pin from the cylinder valve holding the liquefied gas; this procedure has supplanted the technique used in the soda-acid fire extinguisher, which involved combining sulfuric acid with a solution of sodium bicarbonate. Not only is it prudent to have fire extinguishers in your house, but many states requires it. It’s important to have the appropriate fire extinguishers on hand to extinguish common household fires.

To begin, determine which rooms in your home need a fire extinguisher. In the very least, one should be held on each floor of your home. Keep fire extinguishers readily accessible in areas where fires are most likely to occur, such as the kitchen and workshop. Everyone is aware that their office must have a fire extinguisher(s), and everybody should be aware of the location of the closest one. However, several are unaware that a single fire extinguisher is ineffective against all forms of fire. There are different classes of fire extinguishers which comes in variety of various forms, or grades, just like there are several types of fire. To maintain true workplace protection, you must ensure that you have the appropriate fire extinguisher fitted for the possible fire hazards in your home.

Apart from water, a variety of agents are used; the most suitable one is determined largely by the quality of the products being burned. Price, stability, toxicity, ease of cleaning, and the presence of an electrical threat are secondary factors. To begin, it’s beneficial to understand the fundamental components of a burn. Five types of fire extinguishers will be briefly specified for the purposes of this discussion:

  • Class A: Combustible solids that fire freely, such as wood or paper
  • Class B: includes flammable liquids and gases.
  • Class C: energized electrical fire (when an energized electrical source acts as the igniter for a class A or B fire, the fire is no longer classified as a class C fire).
  • Class D: Metallic fuel, (titanium, zirconium, magnesium, sodium)
  • Class K: cooking fires – oils or fats from animals or plants

Regardless of the form of fire, the following four components would still be present:

  • Fuel
  • Heat
  • Oxygen
  • Chain Reaction

The philosophy behind portable fire extinguishers is that eliminating either one or more of these four components would extinguish the fire. Every form of fire has a unique fuel source, heat source, and chain reaction, which is why each class of fire requires a unique model of fire extinguisher. For example, although a class A fire may be safely extinguished with water, a class C fire cannot be safely extinguished with water since the water must perform the energy, posing a risk of injury to the operator.


After establishing a working knowledge of the various forms of fires and why they need specific extinguishers, the following parts would discuss the six main types of fire extinguishers and their applications:

  • Class A

Class A fires are caused by the ignition of common combustible materials such as cloth, timber, paper, rubber, and a number of plastics. A-rated extinguishers are designed to extinguish fires caused by these often combustible products.

  • Class B

Class B fires are caused by highly flammable and combustible liquids such as diesel, wine, oil-based paints, and lacquers. As a result, B-rated extinguishers are equipped to extinguish fires containing flammable and combustible liquids.

Extinguish a fire involving flammable gas only if there is sufficient certainty that the source of fuel can be quickly turned off. Indeed, since the only source of fuel is the escaping petrol, the most effective way to extinguish the fire is to cut off the source of fuel. Extinguishing a flammable gas fire without cutting off the fuel would cause unburned gas to escape into the atmosphere, allowing a hazardous buildup of gas to form. If the gas is introduced to an ignition source, an explosion can occur.

  • Class C

Class C fires occur while electrical appliances is energized. C-rated extinguishers are intended for usage on fires involving energized electrical appliances.

  • Class D

Burnable metals such as magnesium, titanium, and sodium are used in Class D explosions. D-class extinguishers are intended to put out fires involving combustible metals.

Common extinguishing agents can respond with a combustible metal fire, exacerbating the blaze. The most frequently used way of extinguishing a combustible metal fire is to cover it with a dry powder, such as sand, that will not interfere with the fuel. If you store or work around combustible metals, call the Fire Prevention Services office for advice about the form and quantity of extinguishing agent to have on hand.

  • Multipurpose Extinguishers Or ABC Powder Fire Extinguisher

The majority of portable extinguishers are rated for use against several types of flames. For instance, a BC-rated extinguisher is appropriate for fires involving flammable liquids and energized electrical equipment. An ABC-rated extinguisher is appropriate for use on fires including common combustibles, flammable liquids, and energized electrical appliances. Each danger class should be represented by a symbol on an extinguisher that is rated for use with multiple hazards.

Due to the fact that an ABC powder fire extinguisher is a multi-purpose extinguisher, it is one of the most often used extinguishers.

A powder extinguisher uses a very fine chemical powder, most commonly monoammonium phosphate, to extinguish a fire. This functions like a shield over the flames, suffocating it.

Powder extinguishers are efficient against class A, B, and C fires because they are not conductors of electricity and because they quickly disrupt the chain reaction of a liquid or gas burn, which a water extinguisher cannot do.

  • Carbon Dioxide Fire Extinguisher

Carbon dioxide (CO2) fire extinguishers are one of the more environmentally friendly forms of extinguishers to use since they leave zero trace and entail no cleanup.

CO2 extinguishers achieve just that – they extinguish CO2. Through doing so, it depletes the oxygen supply to the fuel, essentially suffocating it. It is ideal for class B fires involving flammable liquids as well as electrical fires.

  • Chemical Fire Extinguisher For Wet Condition

The wet chemical extinguisher is a specific form that is mainly used to extinguish class K fires, which are those that include cooking media such as animal or vegetable fats or oils.

This extinguishers provide a potassium-based solution that efficiently attacks fires in two directions.

To begin, the liquid mist it sprays works like a fire extinguisher. Second, as a result of the solution’s chemical reaction with the cooking medium, a dense soap-like film emerges, sealing the liquid’s surface and preventing re-ignition.

Thus, the wet chemical extinguisher is suitable for use in a kitchen and on class K fires. However, it is also useful in class A fires caused by a combustible substance such as wood or paper.

Where deep-fryers and/or griddles are used to cook large quantities of food, extinguishers with a K rating are typically needed. A commercial kitchen, similar to those seen in restaurants and cafeterias, is an example.

  • Fire Extinguisher Of Water Mist

The water mist extinguisher, utilizes a more modern technology that is effective against the majority of fire groups.

This form of extinguisher discharges microscopic water molecules that assist the firefighter on many levels. To begin, since such a large amount of water is dispersed in such a microscopic fog-like manner, the oxygen content in the air is reduced, assisting in suffocating the flames.

Second, as water often does, the water ions are attracted to the fire and serve to cool it, lowering the temperature.

Finally, and even most importantly, the water has been de-ionized in the water mist extinguishers (the minerals have been removed). As a consequence, it can be used on electrical fires since the de-ionized water does not serve as a conductor, as well as on burning liquids/gases that a normal water extinguisher cannot.

As a result, a water mist extinguisher is both secure and reliable for usage on fires classified as A, B, C, or K.

  • Foam Fire Extinguisher

Foam fire extinguishers are efficient against class A and class B flammable materials, but are ineffective against gaseous flames.

They spray a kind of foam that spreads as it comes into contact with the air, blanketing the flames. This blanket stops the vapors emerging from the liquid from supplying oxygen to the flames, effectively robbing it of fuel. Additionally, since the foam is water-based, it has a cooling impact.

Although foam extinguishers are ideal for liquid fires such as oil, they may also be used to extinguish Class A fires containing strong combustibles such as wood.

  • Clean Agent Fire Extinguisher

A clean agent extinguisher is a form of gaseous extinguisher. As sprayed and reacts with the environment, it transforms to a gas that is non-conductive, healthy to use around people, leaves no trace, and has a very limited ambient lifespan, rendering it eco-friendly.

The gas, which is often made of Halon, puts out fires by reducing oxygen levels and impeding chain reactions. It is suitable for rooms or companies that include electrical and computing devices due to its non-conductive nature and cleanliness. They are sometimes used to extinguish class B and C explosions.


Since you’ve made your transactions, familiarize yourself with the fire extinguisher instructions and ensure that you’re able to extinguish a fire. Fire extinguishers are typically very simple to use in the event of a fire. The majority of forms use the P.A.S.S. technique:

  1. Pull the pin from the fire extinguisher to disabling the tamper seal.
  2. Aim the fire extinguisher short, with the nozzle directed toward the fire’s foundation.
  3. Squeeze the fire extinguisher’s handle to unleash the extinguishing agent.
  4. Sweep the nozzle from side to side when aiming it at the fire’s base before the fire is extinguished.

Repeat the previous three phases if the fire re-ignites.

Before an accident happens, familiarize yourself and your whole family, including infants, with how to use a fire extinguisher. Recognize the location of the extinguishing agent and practice pointing it at a source. Simply avoid pulling the pin or squeezing the handle, since this would rupture the seal and render the extinguisher inoperable. If you’re through training, make a list of the expiration date on – fire extinguisher in your home and schedule their replacement in your calendar.

Now that you are better knowledgeable, you should inspect your property’s extinguishers and ensure you have the kind of extinguisher that will most definitely be used in the event of a fire at your plant. Bear in mind that various styles of extinguishers can be needed in different areas of the plant. That being said, it is not just a matter of getting the appropriate facilities. If the equipment is not maintained properly or if the workers are not properly equipped, it will malfunction or be misused. To guarantee that you have the most appropriate fire extinguishers on your property, to undergo adequate instruction, and to have the extinguishers inspected for accuracy and effectiveness.