AFFF Fire Extinguisher

Fire-extinguisher-SystemAfff Fire Extinguishers

An Afff fire extinguisher is a crucial piece of equipment for any business or home. The main thing about an Afff fire extinguisher is that it’s unique because unlike other types of fire extinguishers, it can be used on both Class A and Class B fires. For those who don’t know what Class A and B fires are, they are typically wood, paper, or cloth fires as opposed to flammable liquids or gases which would be considered a class C fire. In order to have the best chance at stopping a potential blaze from getting out of hand, you will need three things: knowledge, preparation, and the proper tools including an afff unit that can help you fight either a class A or a class B blaze.

In order to effectively use an Afff fire extinguisher, all you have to do is point the nozzle of the unit at the base or seat of the fire and spray a steady stream for a few seconds. Most Afff units are able to put out a small kitchen fire within 30 seconds, but it’s important to make sure that any blaze is out before you leave the area or attempt to do anything else. Afff extinguishers are known for being one of the most reliable and efficient on the market, but they aren’t perfect because there is no way to tell if a fire is going to be put out by a small amount of Afff agent or not. This means that using an Afff extinguisher on a blazing inferno would be dangerous because the Afff unit will run out of propellant before all of the flames are gone.

Once the Afff agent is depleted, you should immediately go and get another Afff fire extinguisher in order to avoid any permanent property damage or risk of injury. Afff units typically come with a wall mount, but there are also Afff extinguishers that come with wheels for easy transport.

Why do We Need Afff Fire Extinguishers?

Afff Fire extinguishers are designed to be used on fires that are small or relatively easy to control. They should not be used for large, uncontrollable fires since they are not powerful enough. It’s important to always read the instructions carefully before using a fire extinguisher, as each one is different and can have side effects if misused. One common mistake people make when using a fire extinguisher is aiming it at the base of the flames instead of at nearby materials that could ignite if left unchecked.

The high-pressure stream can cause severe damage to the eyes, so it is important that you remain behind the fire extinguisher at all times.

Another common mistake people make is attempting to “put out” a grease fire by smothering it with baking soda or flour. This creates a highly flammable paste that may explode in your face when you throw the powder onto the fire. Instead, cover the pan with a lid and leave the room immediately. AFFF Fire extinguishers are important tools for protecting buildings and people from fire.

When to use an AFFF Fire Extinguisher

An AFFF fire extinguisher is a type of fire extinguisher that can be used on both Class B and C fires. When used, AFFF fire extinguishers coat the surface of the burning liquid with a layer of foam. When applied correctly, this can be more effective than using a standard dry chemical fire extinguisher.

AFFF is short for “aqueous film-forming foam.” When you pull the safety pin and squeeze the handle on an AFFF fire extinguisher, a mixture of water and foam is sprayed onto the surface of the burning liquid. When properly sprayed, AFFF extinguishers can be show its effects on Class B fires using flammable or combustible liquids such as gasoline, kerosene, grease, and oil. They are also effective on Class C fires involving energized electrical equipment such as appliances, switches, circuit breakers, or wiring.

AFFF fire extinguishers are not recommended for use on fires involving cooking oils and grease (Class F) because the foam coating can cling to food products, delaying the cooling effect of smothering the fire. Although some AFFF fire extinguishers may be suitable for use on Class A fires, the “D” designation is more appropriate. When in doubt on what type of fire extinguisher to use or how then to properly use one, always check your local building codes before attempting any home fire safety strategy.

Chemical Composition of AFFF fire Extinguisher

AFFF fire extinguishers are made up of a mixture of chemicals, the primary one being ammonium phosphate.

Ammonium Phosphate

chemical formula NH4H2PO4

The chemical is derived from ammonium sulfate and phosphoric acid.

Ammonium fluorosilicate, also referred to as AFFF, causes chemical reactions in the fuel that extinguish or control flammable liquid fires. The chemical produces a foam blanket over the liquid being protected that removes the oxygen from the fuel surface and chemically reacts with the fuel, rendering it non-flammable.

Sodium Alkyl Sulfate

Chemical formula CH3(CH2)nOSO3Na

The chemical is derived from the reaction of fatty acids and alcohol. It is used as an emulsifier, wetting agent, and dispersing agent.

AFFF fire extinguishers have a pH between 8 to 10 which can collapse metals it comes into direct contact with.

Perfluorooctanoic acid (PFOA)

chemical formula


The chemical is a byproduct in the process of producing Teflon. It is used in chemical processes to etch glass and films for high-temperature applications. PFOA has a boiling point between 250°C and 300°C, which exceeds the melting point of steel at 550°C.

The chemical is highly corrosive in the chemical composition of AFFF fire extinguishers when it comes into contact with metal.


chemical formula CF3(CF2)n-C6H4-O-(CF2)n-CH=CH2

The chemical is derived from the reaction of natural oils and hydrogen fluoride. It produces a fluorine-linked carbon structure that can be resistant to chemical degradation or oxidation. The chemical is non-hazardous, biodegradable, and environmentally safe.

Ammonium Fluorosilicate

chemical formula chemical reaction NH4H2PO4 + 2HF → CF3(CF2)n-C6H4-O-(CF2)n-CH=CH2 + NH4F + H2O

The chemical reaction is created by combining ammonium phosphate and hydrogen fluoride.

The composition of AFFF fire extinguishers makes them safe to use on class B fires which include paper, wood, rubber, textiles, etc. They should never be used on class A fires such as natural gas or oil because they provide no protection against these types of substances and may cause the fire to spread quickly since they produce heat when in contact with them.

AFFF fire extinguishers are also useful in absorbing harmful chemical fumes created by burning substances.

This chemical composition will be stored inside the extinguisher when it is not being used. When the handle of an AFFF fire extinguisher is pulled, this chemical enters into a reaction with the surrounding oxygen which creates a large amount of foam. A chemical reaction of this type is often used to produce fire-extinguishing foam.

The chemical works by cooling the surrounding area and starving the fuel source from oxygen, thus terminating any combustion process. This chemical mixture also limits the spread of the fire since it absorbs heat and moisture which would otherwise burn and fuel a fire. AFFF fire extinguishers are made up of 90% chemical and 10% water which also helps to limit the spread of a fire if it is not completely extinguished during your initial attempt.

The chemical composition of AFFF fire extinguishers makes them more effective than dry chemical extinguishers because they can be used on all types of class B fires but their chemical will not harm any class A fires. Dry chemical extinguishers only work on class B fires but cannot be used on class A fires.

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