Grease fires are one of the most dangerous fire types because oil can splash and spread to other areas. According to the National Fire Protection Association (NFPA), about 20% of reported cooking fires spread beyond the origin. 

Oil, fat, and grease can easily catch and sustain fire, making them more dangerous than other causes of fire, like paper. They are also tricky to put out because water makes them worse. So, if there’s a grease fire in a kitchen, which class of fire extinguisher should be used? Find out below. 

How Do Grease Fires Start in Kitchens?

A grease fire starts in the kitchen when cooking oil, fat, or grease becomes extremely hot. 

First, it boils. Once the oil reaches its boiling point—around 450°F for most cooking oils and 375°F for animal fats like lard—it starts to smoke. If you don’t pay attention, it will catch fire because of the ignited vapor and droplets.

Different cooking fats (like butter or bacon) and plant-based ones (like vegetable oil) cause grease fires. If you don’t clean your pans, pots, stoves, and ovens regularly, grease can build up and become a serious fire hazard. Grease fires, also called Class K fires, can spread quickly, especially when there are many flammable items in your kitchen. 

So, what actions cause these fires? There are some common reasons people often neglect. For one, heating oil too quickly causes grease fires. If you turn the heat up too quickly, the oil can reach its smoking point faster. For example, if you’re frying chicken and crank the heat immediately, the oil can smoke and catch fire before you even realize it. 

Dropping frozen food into hot oil can also cause a grease fire. The water in the frozen food can make the splash and smoke the oil. Imagine trying to fry frozen beef—if you drop it in the pan without thinking, you’ll probably end up with a dangerous blaze. 

Leaving boiling oil unattended is another reason. If you leave the stove on for just a minute—maybe to grab a drink or call someone—the oil can go from bubbling to blazing in no time. For instance, leaving a pot of oil on the stove to answer the door can start a grease fire. 

So, never leave hot oil unattended, and make sure you have a fire blanket, fire spray, or fire extinguisher nearby. Knowing how to put out a grease fire can save lives and properties. Remember, caution goes a long way in keeping your loved ones safe. 

Common Cooking Oils and Their Smoke Points

Whether you're frying, baking, or sautéing, knowing how hot your oil can get helps. Here are the most common fats and oils with their smoke points:

Which Class of Fire Extinguisher Should Be Used on Grease Fires?

You should use Class K fire extinguishers on grease fires. Class K fire extinguishers are made of wet chemicals, such as potassium acetate, potassium carbonate, potassium citrate, or a combination of the said chemicals. 

The wet chemicals cool the oil or fat below their ignition points. They also produce a soapy blanket on top of the fuel, preventing the fire from reigniting. This process is called saponification. 

Since the chemicals come out as a fine spray, they also prevent the oil from splashing everywhere. Plus, you can safely use them on Class K fires that involve electrical appliances (e.g., putting out an electrical oven grease fire), even though they’re wet. 

Take note: you can only use wet chemical fire extinguishers on grease fires. Using multi-purpose fire extinguishers is a no-no because they’re water-based. 

Water and oil don’t mix, so using water on a grease fire is dangerous. In particular, water is denser than oil. When you pour water into a pan or pot of hot oil, it goes under it. The water then reaches the burning surface and quickly turns into steam. When water turns into steam, its volume expands up to 1,600 times. This sudden expansion splashes the burning oil and quickly spreads the fire to other areas.

How to Put Out Grease Fires

Accidents can happen anytime. If you're cooking with oils and a grease fire starts, knowing how to put it out could mean the difference between burned food and a kitchen in flames. Here’s how to put out grease fires the right way: 

1. Don’t use water to put it out. 

Never use water to extinguish a grease fire. Throwing water on it can cause the burning oil to splash, spread to flammable items, and injure you. Doing this can also turn a small grease fire into a one in seconds. Additionally, the fire can produce toxic smoke, making it hard for you to breathe and see. 

2. Turn off the heat source if possible. 

If you’re cooking and a grease fire starts, remove the heat from the equation immediately. Heat is an element of the fire triangle, so doing this will put the fire out. 

If you’re using a stove, turn it off if possible. If the grease fire is in the oven, leave the door closed and unplug it or turn off the gas supply. Fire thrives on oxygen, so there’s a chance that it’ll go out on its own. Find out how to prevent and put out an oven fire here. 

Take note that you should only turn off the heat source if it’s safe to do so. Otherwise, proceed to the following steps. 

3. Use a fire blanket, fire spray, or fire extinguisher. 

You can use a fire blanket, fire spray, or Class K fire extinguisher to put out a grease fire. 

While fire extinguishers help a lot, they can be expensive, heavy, and hard to store. They might also contain toxic chemicals and leave a mess that’s hard to clean up. 

A fire spray is an easy-to-use, lightweight, and affordable alternative to Class K fire extinguishers. Prepared Hero’s fire spray is also biodegradable and non-toxic. Unlike a fire extinguisher, you can safely use it around your family and pets. 

Here’s a table showing the differences between Prepared Hero’s fire spray and a Class K fire extinguisher:

Another alternative is a fire blanket, which depletes the fire’s oxygen supply. By doing this, it puts out small Class K fires in seconds. It also doesn’t leave a mess because it simply covers the fire.

Unlike fire extinguishers, Prepared Hero’s fire blanket doesn’t expire. You can reuse it as many times as you want as long as it’s not damaged. Plus, you can use it to save someone on fire. 

Here’s a table showing the differences between Prepared Hero’s fire blanket and a Class K fire extinguisher:

4. Evacuate and call the authorities if you can’t put out the fire.

If the flames are getting bigger or spreading quickly, grab your loved ones and leave the house. Follow the RACE protocol if possible. According to US Homeland Security, a small flame can turn into a big fire in less than 30 seconds, so it’s better to be safe than sorry. 

The same thing applies when you don’t feel confident, overwhelmed, or unsafe. Once you’re outside, call the authorities immediately and make sure everyone’s accounted for. Firefighters are trained to handle emergencies, and they’ll do everything to save your property. At the end of the day, you can replace material things but not lives.

How to Prevent Grease Fires in the Kitchen

Cooking can be a lot of fun, but it comes with fire risks. Grease fires can happen faster than you think, so you should know how to prevent them. With some simple habits, you can keep your kitchen safe and cook without worries. Here’s how to prevent grease fires in the kitchen:

1. Stay in the kitchen while cooking. 

Always keep an eye on what you’re cooking. In today’s digital age, it’s easy to get distracted by a TV show or phone call. If you step away, even for a minute, a grease fire can break out. Fire can spread all over your house quickly, so make it a habit to pay attention to what you’re cooking. If you need to leave, ask someone else to watch the stove or oven. 

2. Monitor cooking temperatures. 

Using oil under extremely high heat can cause it to burn and smoke faster than medium or low temperatures. Stick to medium heat when frying or sautéing to keep things safe. If you’re unsure what the right temperature is, start low and gradually increase it. This way, you can control the temperature without risking a grease fire.

3. Don’t use excessive oil. 

Using the right amount of oil when cooking makes a huge difference. Too much oil increases the risk of spills or leaks. Start with a small amount and add more if needed. If you’re frying something, avoid filling half of the pan with oil. Doing this gives you some wiggle room. Plus, using less oil makes your meals healthier.

4. Keep flammable items away from hot oil. 

Keep flammable items like paper towels, cleaning rags, and wooden utensils at a safe distance from hot oil. Remember, a little organization goes a long way in preventing grease fires. Plus, be careful where you place your tools when cooking. Keep them within reach but away from hot oil and heat sources. 

5. Store cooking oils properly. 

Keep your oils in a cool, dry place and away from heat sources like the stove or oven. Constant exposure to heat can degrade the oil’s quality and increase the risk of fire. In addition, make sure the bottles are tightly sealed to avoid spills or leaks. 

6. Clean your kitchen regularly.

Regularly wipe down surfaces, especially your stove and oven, to remove any grease buildup. Grease can build up quickly and become a fire hazard if not cleaned. 

Make it a routine to check for spills or splatters after cooking and clean them up immediately. Don’t forget to clean under appliances, too, since grease can hide in hard-to-reach spots. Remember, a clean kitchen is a safe kitchen. Plus, it makes your cooking experience worry-free and fun.

Conclusion

Knowing how to put out grease fires keeps your loved ones and property safe. If there’s a grease fire in your kitchen, use a Class K fire extinguisher. 

But if you can’t afford or have one, use alternatives like fire sprays and fire blankets. They’re lightweight, easy to use, and safer around your family and pets. Plus, they don’t leave a mess like traditional extinguishers do. Remember, being prepared and knowing what tools to use makes all the difference in keeping your kitchen safe.