Wet Chemical Fire Extinguishers
Wet chemical fire extinguishers tackle fat and grease fires in kitchens (Class F), for example deep fat fryer fires. In addition, some wet chemical extinguishers can tackle Class A fires (wood, paper etc) and Class B fires (eg petrol). We also stock specialist ABF foam kitchen fire extinguishers for smaller applications.
Wet Chemical Fire Extinguisher – What Colour Band And What Is It Used For?
Wet Chemical fire extinguishers contain a liquid extinguishing agent which is used to smother fires ignited from cooking oils and fats.
Knowing how and when to use your fire extinguisher is essential to ensuring safety in your office/household.
Wet Chemical Fire Extinguisher – What Colour Band?
Wet chemical fire extinguishers come in an all red cylinder with an oatmeal coloured band running around the top.
When To Use A Wet Chemical Fire Extinguisher?
Wet chemical fire extinguishers are recommended to extinguish class A and class F fires.
Wet chemical fire extinguishers are highly recommended as a safety precaution within commercial kitchens where it is more common for a fire to ignite, involving cooking oils and fats.
They are the only type of fire extinguisher recommended to fight this type of fire.
Commercial kitchens are also recommended to have a foam extinguisher and a CO2 extinguisher on site as a precaution for all fire risks that could occur.
To learn more about the different types of fires and fire extinguishers, please refer to this detailed chart.
Wet Chemical Fire Extinguisher
How Does A Wet Chemical Fire Extinguisher Work?
All fire extinguishers work by removing one or more of the 3 key elements that are required for a fire to flourish.
Wet chemical fire extinguishers are filled with potassium, which cools and lowers the temperature of the fire, therefore stopping the fire from spreading.
When the fire extinguisher is used, the potassium sprays out in a fine mist which then reacts with the fats and oils in the fire (class F fire). This creates a soapy layer on the surface which smothers, cools and extinguishes the fire.
It is advised that Wet chemical fire extinguishers, foam extinguishers and water extinguishers should never be used on fires that involve electrical appliances and equipment (class E fire.)
Class F Fire
Advantages of Wet Chemical Fire Extinguishers
Wet chemical fire extinguishers provide fast reduction in the event of a class F fire. By leaving a foam like barrier, it reduces the chances of the fire reigniting. The low pressure of the extinguisher eliminates the risk of the hot fats and oils being splashed around. This prevents injury from burns and reduces the chance of the fire spreading. Clean up after use is quick and easy.
Wet Chemical Fire Extinguisher Sign
Disadvantages of Wet Chemical Fire Extinguishers
The solution inside a wet chemical fire extinguisher is alkaline, this means that it could corrode some metals, especially aluminium. Eyes and skin could become irritated when used so prompt clean up his highly recommended. A wet chemical fire extinguisher MUST NOT be used on electrical fires.
How To Use Wet Chemical Fire Extinguishers?
The working process of a wet chemical fire extinguisher involves 4 simple steps called the PASS technique.
This is a universal process for all fire extinguishers on the market.
The PASS technique is as follows…
Pull the pin. Aim it at the fire. Squeeze the handle. Sweep from side to side.
See our detailed guide: How to Use a Fire Extinguisher.
PASS Technique Fire Extinguisher
Whether it’s your home, office, or business, everyone who lives or works there should know where the fire extinguishers are located. They should also be aware of its capabilities, limitations, and should know how to use it. Wet chemical fire extinguishers are most commonly used for class F fires, although they can also be used for class A fires, replacing a plain air/water fire extinguisher. Class A fires involve materials such as paper, cardboard and wood.
Our range of available include: 2 Litre, 7 Litre
For our detailed articles on other types of fire extinguishers click one of the below links:
Where Can Be Used?
Class F fires; cooking fires that include the use of cooking oils, fats, lard, olive oil, and vegetable oil Class A fires; fires that involve flammable solids like wood, textiles, and paper
In addition, some of the chemical fire extinguishers that exist are allowed to be used in the case of a Class B fire (a fire that involves flammable liquids such as paint, diesel, and petrol). It is essential to check the label or to seek the advice of a fire safety professional in advance if you wish to have a fire extinguisher that can be used on such fire types.
Where Can Wet Chemical Fire Extinguishers Not Be Used?
Wet Chemical Extinguisher There are several instances when a should never be used, these are as follows:
Class B fires; fires that involve flammable liquids (as noted above, this is with the exception of chemical fire extinguishers that have been cleared for such instances) Class C fires; fires that involve flammable gases, for instance, butane and methane Electrical fires
How Do You Identify a Wet Chemical Fire Extinguisher?
You can easily identify a wet chemical fire extinguisher by looking out for the following:
There will be a YELLOW-coloured label on the body of the extinguisher, which will read – WET CHEMICAL The hose will be longer than typical fire extinguishers and will also have a lance attachment You should see an ID sign nearby which will read – WET CHEMICAL EXTINGUISHER
What Are Wet Chemical Fire Extinguishers Also Known As?
A wet chemical fire extinguisher can be known as one of two other names These are as follows:
Class F fire extinguisher Class ABF fire extinguisher (only certain versions can have this name applied to them)
How Do Wet Chemical Fire Extinguishers Work?
Potassium is the chemical element that is used in a Potassium salts are created as a fine mist that is sprayed out and then causes a reaction so that a soapy layer is formed on the surface of the fire.
The mist is fine to not spread the burning oil and works to create a cooling effect and smother the fire.
What Are the Pros and Cons?
This is the sole fire extinguisher appropriate for a fire that involves cooking fat or oil.
Toxic fumes can be created when a wet chemical fire extinguisher is used. Hence the area needs to be very well ventilated after the fire has been put out.
Who Needs Wet Chemical Fire Extinguishers?
All premises that have a professional kitchen or fry foods should also have a. Such premises include the following:
Hotel kitchens Restaurants Burger bars Fish and chip shops
How Do You Use a Wet Chemical Fire Extinguisher?
A wet chemical fire extinguisher needs to be used very carefully as there is a risk of splashing burning fat or burning oil into the nearby areas.
Use the following steps to use a safely:
Remove the safety pin to break the anti-tamper seal and stand at a safe distance If it is safe to do so, switch the heat source off (for instance, the stove or the chip pan) Take the lance and hold it at arm’s length. You should have it at a considerable distance higher than the fire. The nozzle should be a minimum of 1 metre from the flames. Use circular motions to gently spray so that the foam will settle and form a surface on top of the fire Keep spraying so that you use up the full contents of the extinguisher. This will minimize the risk of the fire re-igniting
If you need a fire extinguisher maintenance service, our accredited consultants will attend your sites at a time convenient to you. Contact us today to arrange a visit and decide on the future course of action.
extinguishers are the new kids on the scene, developed specifically for use on deep fat cooking fires. The first such extinguisher on the market was the Chubb FryFighter, and its appearance gave rise to a new fire class, Class F and a new British Standard, BS 7937: 2000.
Wet chemical fire extinguishers are red with a yellow panel above the operating instructions.
How Wet Chemical Fire Extinguishers Work
Normal fire extinguishers are worse than useless in a deep fat fire, since they cannot cool the oil and cause hot oil to splash up on contact with the extinguisher’s agent. Fat can burn at 340 degrees, and an average fat fryer holds up to 75 litres of oil.
Unfortunately, until the invention of the wet chemical extinguisher, many commercial kitchens were supplied with foam or powder units with the occupants falsely thinking these could be used on the fat fryers. The cost can also be high compared to other extinguishers but the risks are much higher in the kitchen and, if bought online at a discounted, the costs are not high these days.
The active ingredient in a is potassium acetate, often with added potassium citrate or potassium bicarbonate. When operated, a wet chemical extinguisher creates a fine mist, which cools the flames and prevents splashing.
The potassium salts then have a saponification effect on the oil’s surface, creating a thick, slippery foam layer that smothers the fat and prevents re-ignition. The chemical foam will also cool the fat over a prolonged period of time.
Unlike other extinguishers, the idea is to completely empty the contents into the fat fryer to enable the cooling process to begin.
A point to note is that the contents can be corrosive so the quality extinguishers are made from stainless steel. Beware of the cheap Middle-Eastern imports made from mild steel as the lifespan will not be as good and the linings could be affected.
: Here’s the Science
is the same process used to create soap from fats and oils as a result of a reaction with a metallic alkali, or base. The base acts on the oil to convert it into hydrolyzed acid and alcohol. Essentially, a converts the surface of the cooking oil or fat into a non-combustable soap.
An added benefit is that the soap-creation process is endothermic, meaning it absorbs heat energy from the oil, cooling the oil down in the process.
Using a Wet Chemical Fire Extinguisher
Like other specialist fire extinguishers, the has a long lance, allowing the user to stand well back from the fire and to spray the agent gently and evenly over the fire’s surface. As with all specialist extinguishers, full training should be given in the proper and effective use of this extinguisher, a common sight in commercial kitchens and food manufacturing environments.
Just Fats, Please
Wet chemical fire extinguishers only work with animal fats and vegetable oils, so they cannot be used on Class B fires involving flammable liquids such as petrol or diesel.
They have usually been tested to a 13A Class A rating but should not be specified for anything other than a kitchen.
Wet Chemical Fire Extinguishers and Electricity
Wet chemical fire extinguishers are not designed for use on electrical equipment, but in the modern kitchen environment, it is hard to avoid electricity cables. Hence, the lance of a standard extinguisher is non-conductive, and passes the 35kv conductivity test.
Other Fire Extinguishers in the Commercial Kitchen
extinguishers have a very specific function, and are not suitable for other types except Class A fires if no other is available.
Most Fire Risk Assessments would recommend that extinguishers are kept in proximity with other fire safety items such as a CO2 for electrical items, and a substantial fire blanket such as a 1.8m x 1.2m size. Fire blankets should be used to smother small pan fires, not to deal with commercial fryer fires.
A small fire blanket is a useful fire safety device for any kitchen, commercial or domestic. Simple to use, yet effective, it should be used to smother a fire and then LEFT ALONE for a considerable length of time to ensure the fire is completely extinguished. If in doubt, smother, get out, stay out and call the Fire Brigade.