What is the difference between Class A foam and Class B foam?

There are many different types of foam for firefighting: Class A foam is used for combustibles, structural fires and wildfires; Class B foam is used for ignitable liquids, like gasoline and diesel; and polar solvent foams help extinguish alcohol-based liquids and alcohol-type fuels.

What is class B foam used for?

Class B Foam Agents are the ideal fire suppression choice for hazards involving flammable and combustible liquids. A foam blanket is formed that works to prevent the release of fuel vapor and separates the fuel from the air it needs to burn. The water content of the foam provides a cooling effect.

Can you mix Class A and Class B foam?

Class A and Class B foam should never be applied simultaneously or on top of one another. While mixing foams during foam application on scenes can render an operation ineffective, mixing foams in storage can cause the foam to degrade and become ineffective when used.

What is Class A firefighting foam?

Class A foams are used to extinguish fires caused by wood, paper, and brush. Class A foams generally do not contain per- and polyfluoroalkyl substances (also known as “PFAS”).

What is the two basic types of foam?

Protein foams contain natural proteins and are generally biodegradable; synthetic foams are made of synthetic foaming agents.

Class A Foam Pt 1

Is AFFF Class A or B?

Class B Foam (also called AFFF): Used to extinguish Class B materials, which include gasoline, oil, and jet fuel.

Can you use Class A foam on Class B fires?

It's obvious that Class A foam is used to fight Class A fires, and that Class B foam snuffs out the Bs.

How many types of fire foam are there?

This standard amalgamates first three parts, namely, Part 1 Protein foam concentrate, Part 2 Aqueous film forming foam (AFFF) and Part 3 Fluoro-protein foam. The purpose of all the three types is same, that is, for use in Fire Extinguishing agent for Class 'A' and 'B' flammable liquid (Hydrocarbons) fires.

Which one is a Class B fire?

Class B: Flammable liquids such as alcohol, ether, oil, gasoline and grease, which are best extinguished by smothering.

What is class A foam made of?

Class A foams consist of a mixture of water, foam concentrate, and air. The composition of the foam depends on the proportion of the three components. The two most common methods for producing class A foam are nozzle-aspirated foam systems and compressed air foam systems (CAFS).

What are the types of foam used in firefighting?

Common types of persistent firefighting foams are AFFF, FP, FFFP, and their alcohol resistant varieties.

What percent is Class A foam?

Class A foam is typically proportioned from 0.3% to 1%.

What is the difference between AFFF and AR AFFF?

AFFF and AR-AFFF consist of essentially the same ingredients. These typically include fluorosurfactants, hydrocarbon surfactants, solvents, inorganic salts, corrosion inhibitors, water; and in the case of AR- AFFF, a polymer which is typically a polysaccharide.

Does Class A foam expire?

The effective life of CLASS A PLUS foam concentrate can be maximized through optimal storage conditions and proper handling. CHEMGUARD concentrates have demonstrated effective firefighting performance with contents stored in the original package under proper conditions for more than 10 years.

Why do firefighters use foam instead of water?

Class A foams are used to lessen the surface tension of water, which improves the wetting and saturation of water used to fight Class A fires, which are fueled by ordinary combustibles.

What is Class A extinguisher?

Class A fires involve ordinary combustible materials, such as cloth, wood, paper, rubber, and many plastics. Extinguishers with an A rating are designed to extinguish fires involving these ordinary combustible materials.

How can you tell the difference between Class B and fire?

Class B fires are not really different from other fires in that they have the same basic “fire tetrahedron” elements. In order to have a fire, you need fuel, oxygen, heat and a chemical reaction. The only difference is the fuel. The fuel for a Class B is a combustible gas or liquid.

Is high expansion foam to fight a fire on deck?

If we use high expansion foam for deck fires, the foam will fly with the wind and will not be able to extinguish the fire. For this reason, for deck fires low expansion foam is used. On tankers, it will always be low expansion foam for fires of the cargo area.

What kind of foam is AFFF?

Synthetic foams

Aqueous film forming foams (AFFF) are water-based and frequently contain hydrocarbon-based surfactant such as sodium alkyl sulfate, and fluorosurfactant, such as fluorotelomers, perfluorooctanoic acid (PFOA), or perfluorooctanesulfonic acid (PFOS).

What do you mean by 6% foam concentrate?

This high quality AFFF (aqueous film forming foam) concentrate is supplied in a 20lt drum. The concentrate requires 94 parts water to 6 parts concentrate. The foam concentrate is ideal for refilling foam / air fire extinguishers and for use with fire hoses (with appropriate foam branch equipment).

Which type of foam is best used on wildland fires?

Class A foams are designed specifically for fighting fires in class A fuels.

Why do airport fire trucks use foam?

The chemical composition of foam helps break down water surface tension, allowing water to penetrate burning materials, and thus, making water work more efficiently. Reduce the amount of water required to fight fires. The use of foam extends the usable amount of water on the apparatus.

What type of foam clings to vertical surfaces?

The expanded foam solutions also create a dense foam blanket that clings to vertical surfaces and provides an insulating barrier between the fuel and the air. Chemical Foam has been classified in different ways over the years.

Does Class B foam contain PFAS?

The vast majority of the Class B fire- fighting foam in stock or service in the United States is aqueous film-forming foam (AFFF) or alcohol-resistant aque- ous film-forming foam (AR-AFFF). 1 These foams contain PFAS. Class B foams that are fluorine-free do NOT contain PFAS.

When using foam a Class B fire is extinguished by?

Foam extinguishes Class B Fires by covering the flammable liquid with a foam blanket, thus cutting off the oxygen supply from the combustion process. The water content of the foam will help lower the temperature of the flammable liquid.