When you work in a busy restaurant kitchen, things are chaotic, accidents happen. But hot cooking oil and open flames, when combined, can lead to small mishaps becoming dangerous fires. It is important to understand what causes these kitchens grease fires, learn how to extinguish them safely and have the right fire suppression equipment on hand to work in a safe environment.
In this article, we will give an overview of kitchen grease fire hazards, describe strategic response steps to take if a fire breaks out, and explain more about class K extinguishers used in commercial cooking areas.
What Factors Lead to Grease Fires in Restaurant Kitchens?
Grease accumulation on stovetops, ovens, grills, and deep fryers provides fuel to spark flames. As oil heats up during the cooking process, it can begin to smoke, boil, and eventually ignite into fire under certain conditions. Failing to notice these early warning signs or not lowering temperatures allows the oil to reach its auto-ignition point. Unattended grease buildup also continues to absorb heat and pose an extreme fire hazard.
Several variables cause oils to combust more readily:
- High cooking temperatures – Heating fats and vegetable oils past their smoke points causes fire risk. Different oils have varying smoke points based on their molecular structures.
- Overcrowded cooking surfaces – Too many pans clustered together traps in heat and facilitates flare-ups.
- Lack of ventilation – Proper kitchen hoods help capture excess grease vapor and heat before they accumulate.
- Distractions – During hectic meal services, it’s easy to lose track of what is happening on the stovetops. Staying focused and attentive is vital.
Initial Steps to Follow When a Grease Fire Starts
If a grease fire does occur in the kitchen, follow these immediate response guidelines:
Shut Off the Heat Source
The very first step is to turn off the stove, deep fryer, or any equipment providing heat that is fueling the flames. For gas appliances, manually shut off the fuel valve. Electric units can simply be powered down at the switch or unplugged. This eliminates the energy input that is causing the oils to combust.
Cover the Container with a Lid
After the heat source is off, place a tight-fitting lid or metal tray over the burning pot, pan, or deep fryer. This helps smother the fire by blocking external oxygen. The lid also traps heat and choked combustion gases so flames cannot survive. Use a flat cover that fully seals the rim rather than a loose or domed lid with gaps.
Baking Soda for Minor Stovetop Fires
For a small grease fire confined to a pot or pan, baking soda can work very effectively after covering to deplete oxygen levels. While maintaining the lid’s position, carefully pour 1-2 heaping spoonfuls of baking soda directly into the container over the flames. The bicarbonate reacts with fatty acids in the oils to remove heat energy from the system so fire cannot persist.
Class K Extinguishers for Large / Spreading Fires
If flames have extended beyond the original cookware or do not extinguish right away with baking soda treatment, it is imperative to safely evacuate from the area and activate the kitchen’s class K fire extinguisher. These specialty extinguishers contain potassium-based agents designed to combat animal fats, vegetable oils, and other hot grease fires. Using the wrong type of extinguisher can allow the fire to spread rapidly or even explode in certain situations.
Common Mistakes to Avoid
In the stress of an emergency, it’s natural to panic and forget proper protocols. However, certain actions when trying to extinguish a grease fire can make the situation exponentially worse:
- Tossing water onto burning oils can cause violent boiling overflows.
- Adding flour or baking powder to flames can combust into explosive dust clouds.
- People often confuse baking soda and baking powder. However, baking powder contains additional acidic agents that adversely react with hot greases.
The Unique Properties and Hazards of Class K Cooking Fires
Commercial kitchen operations utilize large amounts of fats and oils for frying, sauteing, grilling, and other cooking methods. When these oils are heated beyond their working temperatures, they can ignite and sustain intense fires. Burning animal fats and vegetable oils pose unique challenges compared to other materials:
- Highly Flammable – The long molecular chains in these oils hold a lot of potential energy that gets released as fires spread rapidly.
- Difficult to Extinguish – Class K fuels release their energy quickly and reach very high temperatures that continue driving the combustion reaction even after removing the heat source. The oils essentially create their own self-contained firestorm.
- Re-Ignition Risks – Because the fuels are liquid, they can splash or seep into adjacent areas during suppression efforts and reignite fires once oxygen returns.
- Toxic Smoke – Burning fats and oils put off dense, noxious smoke that contains carbon dioxide, carbon monoxide, soot, and other dangerous compounds.
Specialized Class K Fire Extinguishers
Class K extinguishers contain powerful potassium acetate, potassium citrate, or potassium carbonate agents tailored specifically to extinguish burning cooking oils. When deployed onto hot grease fires, these specialty wet chemical mixtures release heat-absorbing vapors that help cool oils below their auto-ignition points.
The potassium ingredients also create physical barriers between the oils and oxygen to bring flames under control. Chemical coatings form across the surface of oils to separate them from oxygen and halt the combustion reaction. Class K agents essentially smother and displace oxygen rather than chemically interrupting the fire as some other extinguishers aim to do.
Installing dedicated class K fire extinguishers specially engineered for commercial kitchens provides the right suppression tools for likely cooking oil and grease fire events. Positioning larger wheeled models near fry stations supplemented by auxiliary units across the kitchen enables rapid access. Thoroughly train all employees on hazard avoidance, emergency response, evacuation, and proper extinguisher operation. Running regular fire drills ensures everyone stays familiar with protocols during the intensity of dinner services.
Conclusion
When super-heated cooking oils combust within a restaurant, the risks are significant, both to life and property. Yet, knowing what class K fires are and how they differ from other materials helps to plan strategic responses with specialized commercial kitchen extinguishers.
Having proper equipment on hand, keeping it accessible and in working order, and constantly training staff allows for confident emergency action if danger ignites during the dinner rush. Everyone can work smarter, even in hectic kitchen conditions, if they master safety fundamentals and fire dynamics.