Why You Should Never Use Water on a Grease Fire
Last updated: September 4, 2026
Kitchen/Restaurant Bundle
Picture this: You're cooking, the oil in the pan catches fire, and your first instinct is to grab a glass of water.
Stop right there.
Source: National Fire Protection Association (NFPA), Home Cooking Fires: Supporting Tables, Table 9, September 2023. NFPA's 2017-2021 annual average was 22,923 fires involving these materials.
Pouring water on a grease fire can turn a small kitchen fire into a much larger and more dangerous situation in seconds. Water and burning grease do not mix, and understanding why could help prevent serious injuries, property damage, or a devastating fire.
What Happens When You Pour Water on a Grease Fire?
Grease and cooking oil can reach extremely high temperatures. When water hits that hot oil, the water quickly sinks below the surface and can instantly turn into steam.
As the water rapidly expands into steam, it can force the burning oil up and out of the pan.
The result? Burning grease can violently splatter and spread the fire across nearby surfaces.
Source: NFPA reports an annual average of 677 civilian injuries from fires where fat, grease, butter, margarine, or lard were the first material ignited.
Instead of putting the fire out, water can cause the flames to spread beyond the pan and potentially ignite cabinets, countertops, clothing, or other nearby materials. The U.S. Department of Agriculture specifically warns that using water on a grease fire can cause flaming oil to splatter and spread.
Why Does Water Make a Grease Fire Worse?
It all comes down to how water and oil behave.
Water is denser than oil, so when you pour water into a pan of burning grease, it sinks beneath the hot oil. The intense heat causes the water to vaporize almost instantly.
Steam takes up far more space than the original liquid water, and that rapid expansion can push burning oil out of the pan in all directions.
What may have started as a small fire on the stove can suddenly become a fire involving your entire kitchen.
That's why water should never be used on a grease or cooking oil fire.
Source: NFPA identifies unattended or unsupervised cooking as the leading human factor contributing to cooking fires, 2017-2021 annual average.
"The most dangerous ingredient in a kitchen fire? Leaving the stove unattended."
Fire Prevention Week 2025, USAFP
So, What Should You Do Instead?
The right response depends on the type and size of the fire and whether you can act safely.
For a small pan fire: The U.S. Fire Administration advises turning off the burner and carefully sliding a lid or cookie sheet over the pan to smother the fire.
Do not move the pan. Do not attempt to move the pan, as hot oil can splash and spread the fire.
If you're dealing with a larger fire, or you're unsure whether you can safely control it, your priority should be to get out, get others out, and call 911.
Commercial Kitchens Need the Right Protection
For restaurants and commercial kitchens, grease fires require specialized fire protection.
Fires involving cooking oils and fats are classified as Class K fires. OSHA identifies Class K extinguishers as the type designed for fires involving combustible cooking fluids such as oils and fats.
A Class K extinguisher uses a wet chemical agent designed specifically for hot cooking media. These extinguishers help cool the burning oil and create a barrier that helps prevent the fire from reigniting.
Commercial kitchens may also have fixed fire suppression systems designed to protect cooking equipment. Employees should understand their facility's fire safety procedures and receive appropriate training on how to respond during a kitchen fire.
ABC Isn't Always the Answer
ABC fire extinguishers are incredibly versatile and are commonly used to protect against:
- Class A: Ordinary combustibles like wood, paper, and cloth
- Class B: Flammable liquids
- Class C: Energized electrical equipment
But a grease fire in a commercial cooking environment is a different hazard. OSHA specifically distinguishes Class K extinguishers for kitchen fires involving oils and fats, while NFPA guidance recommends Class K-rated extinguishers for cooking grease fires.
That's why it's so important to make sure your business has the right extinguisher for the hazards in your facility.
Source: NFPA's findings for 2017-2021.
So what kind of fire extinguisher should be used on a grease fire? A Class K fire extinguisher, or a wet chemical extinguisher, should be used on grease fires.
Amerex C260, 6 Liter Class K Kitchen Fire Extinguisher
The Bottom Line: Never Fight a Grease Fire with Water
Remember these key rules:
- Never pour water on a grease fire.
- Never move a burning pan or container of hot oil.
- If it is safe and the fire is small, turn off the heat and carefully cover the pan to smother the flames.
- Make sure commercial kitchens have the appropriate Class K fire protection, and employees understand emergency procedures.
- If the fire cannot be safely controlled, evacuate and call 911.
Fire safety starts with knowing that not every fire should be handled the same way.
At Pro Fire & Safety, we help businesses understand their fire protection needs and find the right equipment for the hazards they face. From fire extinguishers to commercial kitchen fire protection, having the right tools in place can make all the difference.
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🧯 Grease Fire Action Plan
- Turn off the heat if you can safely reach it.
- Never use water on a grease fire, it can cause the fire to spread.
- Cover a small pan fire with a metal lid and leave it covered until completely cool.
- Use the proper Class K extinguisher if it is safe to do so.
- Evacuate and call 911 if the fire grows or cannot be safely controlled.
- Keep your equipment maintained and employees trained so everyone knows what to do before an emergency happens.
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Your Grease Fire Action Plan
Keep these rules in mind before oil ever hits the pan:
- Never use water: Water sinks below hot oil, flashes to steam, and can violently splatter burning grease across the kitchen.
- Small pan fire: Turn off the heat and slide a lid or cookie sheet over the pan. Never move the pan.
- Large or uncontrolled fire: Get out, get others out, and call 911.
- Commercial kitchens: Grease fires are Class K, and require a wet chemical extinguisher, not a standard ABC unit.
- Stay trained: Keep equipment maintained and make sure employees know the procedure before an emergency happens.
Reviewed by Joseph Hedrick, NFPA-certified fire protection specialist
