Fire Extinguisher Classes (A, B, C, D, K): A Complete Guide

Tap a class to see which type of fire it's used for.

Class A Fire

Ordinary combustibles (paper, wood, cloth, etc.) — the most common fire type, which can be put out with water or a general-purpose dry-powder extinguisher.

Class B Fire

Flammable liquids (oil, gasoline, etc.) — using water here can actually spread the fire further, so a foam or CO2 extinguisher must be used instead.

Class C Fire

Electrical fires — using water while the electricity is still live risks electric shock, so a non-conductive extinguisher (such as CO2) is required.

Class D Fire

Metal fires (magnesium, sodium, etc.) — a general-purpose extinguisher is often ineffective or even dangerous here, so a special dry-powder extinguisher made for metal fires is needed.

Class K Fire

Kitchen fires (cooking oil, etc.) — caused by high-temperature oil, these are safer to fight with an extinguisher designed specifically for kitchen fires rather than a general-purpose one.

Using the Right Extinguisher for the Fire Type Matters

Using the wrong class of extinguisher can fail to put the fire out and may even make it worse, or cause a secondary hazard like electric shock. For the home, it's generally recommended to keep a multi-purpose (ABC-rated) extinguisher that covers several classes at once.

Frequently Asked Questions

What kind of extinguisher should be kept in the kitchen?

It's best to keep either a K-class extinguisher specifically designed for cooking-oil fires, or at minimum a multi-purpose ABC extinguisher, near the kitchen.

Why is it dangerous to spray water on an electrical fire?

Because water conducts electricity — using it while the power hasn't been cut off can lead to electric shock.