Wet Chemical Fire Extinguishers: A Complete Guide
Wet Chemical Fire Extinguishers: A Complete Guide
If you’re unsure which fire extinguisher is suitable for cooking oil fires in a commercial kitchen, here’s the answer: wet chemical fire extinguishers. These are the only extinguishers recommended for cooking oil fires, making them essential safety equipment for professional kitchens.
In this guide, we’ll cover all the details about wet chemical fire extinguishers, including how they work, their ingredients, use identification, and much more.
What Are Wet Chemical Fire Extinguishers?
Wet chemical fire extinguishers are highly effective fire-fighting tools specially designed to put out fires containing cooking oils and fats in a commercial kitchen setting. These extinguishers carry an extinguisher with a classification of K means that helps to put out the fires, cool the burning oil, and create a soapy film that seals the surface to prevent re-ignition.
It is strongly advised that wet chemical fire extinguishers be applied to cooking oil appliances only after the electrical power has been switched off. Most commercial kitchen hood fire suppression systems have this feature.
They are simple to operate and produce a small spray that helps prevent hot oil from splashing onto the user or nearby surfaces.
Ingredients in Wet Chemical Fire Extinguishers
The active ingredients used in wet chemical fire extinguishers:
- Potassium acetate
- Potassium carbonate
- Potassium Citrate
These chemicals work together to extinguish the fire of burning oils by reducing heat quickly and sealing the oil in a non-flammable, soapy layer.
How Wet Chemical Fire Extinguishers Work
The chemical element in wet chemical extinguishers is potassium. Potassium salts spray onto the fire like a small mist when they discharge. This mist reacts with the burning oil to form a soapy layer while preventing the spread of the burning fat or oil.
This process works in two critical ways:
- Cooling: The mist cools the fire, lowering the temperature to stop the spread.
- Saponification: Potassium salts react with the hot oil to form a soapy foam, which smothers the flames and creates a barrier to prevent re-ignition.
Sizes of dry powder fire extinguishers available:
- 2 liters
- 3 liters
- 6 liters
When to Use a Wet Chemical Fire Extinguisher
Wet chemical fire extinguishers are specifically designed for:
- Fires are caused by cooking oils and fats (Class F fires).
- Fires involving solid combustibles like paper, wood, and textiles (Class A fires).
They are ideal for professional kitchens with deep-fat fryers or similar equipment.
Important Note: Water can quickly spread a grease or oil fire, hence it should never be used on it.
Pros and Cons of dry powder fire extinguishers:
Pros: Expert dry powder extinguishers are the only extinguishers that can put out flammable metals; they are effective against a lot of fire types and put out fires quickly.
Cons: when used in enclosed areas, the powder can be swallowed and may damage eyesight; it can spread over a vast area and leave a residue; there is a little chance that the fire can re-ignite.
How Do Wet Chemical Fire Extinguishers Differ from Others?
The key difference is their purpose. Wet chemical fire extinguishers are specially made for cooking oil fires, whereas other extinguishers are designed for different types of fires.
Additional features include:
- A longer hose to allow the operator to stand safely away from the fire.
- Ingredients that can conduct electricity, making them unsuitable for fires involving active electrical equipment.
Wet Chemical Fire Extinguisher Uses
These extinguishers are best for:
- Fires contain cooking oils and fats, like lard, olive oil, butter, and vegetable oil (Class F fires).
- Fires contain solid combustibles like wood and textiles (Class A fires).
Some examples may also be approved for Class B fires (flammable liquids) – always check the label before use wet chemical fire extinguishers.
Do Not Use Wet Chemical Fire Extinguishers For:
- Fires containing flammable gases like methane and butane (Class C fires).
- Electrical fires or appliances with an active electrical current.
- Flammable liquids (Class B fires) unless specified on the extinguisher.
How to Identify a Wet Chemical Fire Extinguisher
- A yellow label stating “Wet Chemical.”
- Longer hose with a lance attachment.
- Identification sign nearby, marked “Wet Chemical Extinguisher.”
How to Use a Wet Chemical Fire Extinguisher
When we use wet chemical fire extinguishers need caution to control the spreading the fire:
- First, remove the safety pin to break the anti-tamper seal.
- And now turn off the heat source if it is safe to do so.
- Next hold the lance at arm’s length, at least 1 meter away from the fire.
- Now spray gently in slow with circular motions to allow the foam to settle.
- Then use the entire contents to ensure the fire is fully extinguished and cannot reignite.
Pros and Cons of Wet Chemical Fire Extinguishers
Pros:
- The only extinguisher is suitable for cooking fat and oil fires.
- Prevents re-ignition by sealing the oil.
Cons:
- Can release toxic fumes; ventilate the area after use.
- Not suitable for electrical or gas fires.
Who Needs Wet Chemical Fire Extinguishers?
Wet chemical fire extinguishers should be installed in facilities with deep-fat fryers or professional kitchens. These include:
- Restaurants
- Fish and chip shops
- Burger bars
- Hotel kitchens
These businesses often require additional extinguishers (foam and CO2) to cover all fire risks.
Conclusion
Wet chemical fire extinguishers are the ideal choice for combating Class A and Class F fires, particularly those caused by cooking fats and oils. Their unique design and chemical composition make them indispensable for professional kitchens. Always ensure you have the correct extinguisher for your needs, and consult a fire safety expert if you’re unsure.
For more information or assistance, contact Damia Global Services for expert guidance and a free safety survey.