What do I do if a pan of oil catches fire?

Turn the heat off, smother it, leave it alone — and the two instincts that make it far worse.

Difficulty: beginner
Time: 5 min
Read: 3 min
Safety: restricted

Short answer

Turn the heat off if you can reach it safely, do not move the pan, and slide a fire blanket or a close-fitting metal lid over it from the side. Leave it covered for at least thirty minutes. Never use water and never carry the pan.

Cooking fires are the largest single cause of house fires in the UK, and chip pan and oil fires are the most dangerous kind. The response takes ten seconds and the two natural instincts — throw water, carry it outside — are both catastrophic.

Safety

Never put water on a burning pan of oil — it flashes to steam and throws burning oil across the room in a fireball. Never move a burning pan. If the fire does not go out immediately, or has spread beyond the pan, leave the room, close the door, get everyone out and call 999.

What to do — and never do — when cooking oil catches fire

Step by step

Turn the heat off if the control is safely reachable.Hob knob or the switch. If flames are in front of the controls, do not reach through them — go straight to smothering.
Do not move the pan.Carrying a burning pan spills fire along the route, puts it against your body, and the draught as you walk feeds it. This is how most serious injuries in kitchen fires happen.
Smother it from the side.A fire blanket or a close-fitting metal lid, slid across the top of the pan with your hands and face behind it. Never lower something down onto it from above.
Never use water.Water hitting oil at around 350°C flashes to steam and expands about seventeen hundred times instantly, blasting burning oil upwards and outwards. This is the single most dangerous thing you can do.
Do not use a wet tea towel.The water in it does the same thing on a smaller scale, and the cloth itself catches. A dry fire blanket or a metal lid only.
Leave it covered for at least thirty minutes.The oil is still far above its ignition point. Lifting the lid to check lets air back in and it reignites, often more violently.
Get out if it does not go out at once.Close the kitchen door behind you, get everyone out of the house, and call 999 from outside. Do not go back in.
Keep a fire blanket by the kitchen door.By the door, not by the hob — you want to be able to reach it without walking towards the fire. They cost a few pounds.
Prevent it in the first place.Never fill a pan more than a third full, never leave frying oil unattended, and take the pan off the heat the moment you see wisps of blue smoke — that is the warning before ignition.

Tips

Fire blanket by the door, not by the cooker. You must not have to reach past the fire to get it.
Blue smoke rising off oil means it is close to igniting. Take it off the heat immediately.
Never use a fire extinguisher's water or foam type on cooking oil.

Common mistakes

Throwing water on burning oil — Water is denser than oil so it sinks, hits oil far above 100°C and turns to steam instantly, expanding roughly seventeen hundred times. That expansion ejects burning oil upwards in a fireball that typically reaches the ceiling.
Carrying the pan to the sink or out of the back door — The movement fans the flames, burning oil slops over the sides onto the floor and onto you, and you are holding it at chest height. Fire services see life-changing burns from exactly this.

If it doesn't work

Flames in the pan

Cause: Oil reached its ignition point — Fix: Heat off, do not move it, slide a fire blanket or metal lid over it, leave for thirty minutes.

Fire has spread beyond the pan

Cause: Too late for smothering — Fix: Leave the room, close the door, get everyone out, call 999 from outside.

Blue smoke off the oil

Cause: Oil past its smoke point — Fix: Take the pan off the heat now. It is minutes from igniting.

Small flare-up as food goes in

Cause: Oil splashed onto the burner — Fix: Cover with a lid briefly and reduce the heat. Dry food thoroughly before it goes in.

Questions people ask

Can I use a fire extinguisher on a pan fire?

Only a wet chemical extinguisher, which is rated for cooking oil. Water and foam extinguishers make an oil fire dramatically worse. For a domestic kitchen, a fire blanket is the right equipment.

How do I know when oil is about to catch fire?

It thins visibly, the surface goes still and glassy, and wisps of blue smoke rise from it. That is the smoke point, and ignition follows within a couple of minutes. Take it off the heat as soon as you see smoke.