Because different fuels create different types of fires the types of fires are broken up into what are called Classes of fires. That determines what kind of Fire Extinguisher is used for the area at risk. The most common type of fire in the Kitchen is a grease and oil fire that happens when cooking. What is the Best Fire Extinguisher for use in Kitchens?
A Class K fire extinguisher is used in cooking oils or fats, and it is one of the most common types of fire in restaurants and kitchens. Make sure it is refillable and comes with a wall-mount and an easy-to-read and reliable pressure gauge.
Whether it’s at home or in a commercial Kitchen you will need to make sure that your location has the right type of Fire extinguishers available that will lower the risk of loss to life and property. If you are renting or even at work (that may have a kitchen) the right Fire Extinguisher should be available in the right room.
The Types of Fire Extinguishers and Their Uses
There is a total of 8 Types of Fire Extinguishers to choose from. There are no types that will work on all classes of fire.
- Water
- Water Mist
- Water Spray
- Foam
- Dry Powder – Standard
- Dry Powder – Specialist
- Carbon Dioxide (‘CO2’)
- Wet Chemical
Class A fires – combustible materials: caused by flammable solids, such as wood, paper, and fabric
Class B fires – flammable liquids: such as petrol, turpentine, or paint
Class C fires – flammable gases: like hydrogen, butane, or methane
Class D fires combustible metals: chemicals such as magnesium, aluminum, or potassium
Electrical fires – electrical equipment: once the electrical item is removed, the fire changes class
Class K fires – cooking oils: typically a chip-pan fire
The main distinction among home extinguishers is the size. In most cases, bigger is better, but sometimes the biggest extinguishers are too heavy to maneuver. The weight of a Fire extinguisher refers to the amount of chemical inside the canister that adds several more pounds. There’s also a difference between rechargeable extinguishers, metal valves, and disposable ones, which have plastic valves. A rechargeable one will cost more, but refilling it once the pressure gauge shows that use or time has depleted the contents is still less expensive than buying a new disposable one.
It is the spraying of a load of water at room temperature that will effectively reduce the temperature of the burning things. Water-Fire Extinguishers are best-used fighting fires involving solid combustibles such as wood, paper, and textiles. Water-Fire Extinguishers have a Class A rating and should not be used on any other Class fire.
Class A
fires are ones with everyday combustible materials, such as furniture, curtains wood, paper, rubber, cloths, and even plastics.
One of the most recognizable indicators of a Class A fire is that the fuel sources leave ash behind when they burn. They are the simplest types of fires and involve regular materials most commonly found in homes and offices.
If you spray a burning hot room with water, the water will vaporize. So by spraying water into a burning building in a mist, you’re sucking a huge amount of heat energy from the air and the burning materials. This is how you can control the temperature of a barbecue or grill with a water mister.
As the water vaporizes in the burning room it helps asphyxiate the fire by forming a barrier between the surface of the burning items and the air that contains oxygen that it feeds on to breathe. Fireman uses this process inside burning buildings.
Class B
Class B fires are ones in which flammable liquids and/or gases become involved. They are the fuel source in the fire triangle (fuel, heat, oxygen + chemical reaction).
Flammable liquids include gasoline, diesel fuel, oils, tars, petroleum greases, solvents, alcohols, and oil-based paints. Flammable gases include things like propane, hydrogen, and butane.
The fuel sources of gases and liquids can be quite volatile and cannot be extinguished by water, which will only make the fuel source spread, thus spreading the fire. That is why it is important only to use extinguishing agents and methods designed specifically for Class B fires.
Class C
A class C fire is an “Energized” fire, which in this case, means that it is fed by a power source. Class C fires may begin from a short circuit, faulty wiring, power cord damage, overcharged devices, or overloaded electrical outlets. Any place where electrical equipment is used or electrical wiring is present is a potential site for a class C fire.
Class A-B-C Fire Extinguishers Types & Applications
- Water: A water extinguisher’s purpose is to remove the heat from a fire. It is the simplest solution for the simplest fire class, the Class A fire.
- Foam: This agent cools and suffocates fires and is also largely used for Class A fires.
- Multipurpose Dry Chemical: Multipurpose dry chemical fire extinguishers are effective for Class A fires, Classes B and C. The way the agent in these types of extinguishers works to extinguish a Class A fire is by interrupting the chemical reaction in what’s known as a Fire Triangle (fuel, oxygen, heat plus a chemical reaction).
The standard Class B & C dry chemical fire extinguishers, using a sodium bicarbonate-based agent, are NOT effective on Class A, and are only intended for Class B and C fires. - Clean Agent: These extinguishers use halogenated, or “clean” agents, which avoid contamination of the area and are more friendly to the environment. This agent interrupts the chemical reaction and also cools the material to remove the heating element from the fire. Larger handheld models (11lbs and larger) can be rated for Class A fires, but smaller handheld models don’t contain enough agents to be rated for Class A.
- Water Mist: A relatively new development, Water Mist Extinguishers can also operate as a “clean agent” type, as the mist prevents the types of water damage caused by a regular water extinguisher and is safe to use on live electric wires. This agent removes the heat from a fire and is primarily used as a Class A extinguisher where a potential Class C hazard exists. Certain types of extinguishers may be used on more than just Class A, such as the multi-purpose dry chemical extinguisher, while others are only ever classified as A, such as the water extinguisher.
Kitchen Fire Extinguisher Class k
Never attempt to extinguish a Class K fire (a grease or oil fire) with Water Fire Extinguisher or any water. There are a few reasons. Class K,s normally are hung in Kitchens.
Never use water to put out a grease or oil fire! Why?
Polarity
A molecule is polar when it has a positive charge at one end and a negative charge at the other. Positive ends of water molecules want to bond with the negative end of another water molecule.
Oil and grease molecules are non-polar making it a problem when they try to mix. They want nothing to do with each other pushing each other apart. Do you get the picture?
Another reason is Density
Density is the ratio of mass to volume, or how tightly particles are packed together. Oil has a density between 0.91 and 0.93 grams per milliliter. That slight difference in density is enough to make them separate. In an article called Why Water Can Make a Grease Fire Worse from the Nation Fire Protection Association (NFPA) the Author Dr. Biberdorf says that
If your cooking oil does ignite, turn off the flame and cover the pan with a lid as quickly as possible, the NFPArecommends. That will cut off its oxygen supply and help smother the flames, Dr. Biberdorf says. “I always have a metal or glass lid ready if I’m cooking with grease,” she adds.
Once the fire is out, let the pan cool for a long time, the NFPA advises. Removing the lid too early could cause the fire to start again.
To help prevent the spread of a grease fire, use a damp cloth to wipe your counters before, during and after cooking with oil.
“Any time you see grease on your kitchen counter, you should try to wipe it down in order to avoid a ‘jumping fire,’” she warns. “Essentially, a grease fire will immediately ‘jump’ to any other sources of fuel, which in this case is oil on your counter.”
If you have an oil & grease fire turn off the flame and cover the pan with a lid as quickly as possible, the NFPA recommends. That will cut off its oxygen supply and help smother the flames. Once the fire is out, let the pan cool for a long time, the NFPA advises. Removing the lid too early could cause the fire to start again.
Water is truly a wonder of this world. There are many things that water does that can’t be explained but some can. Because of Thermal Capacity, Water is effective in fighting fires but not all types of fires. Learning what type of fire extinguisher is right for your home or business could save your life and property. Take the time to learn Fire Safty.
JimGalloway Author/Editor
