Different Types of Fires and How to Extinguish Them
Learn to identify the 5 fire classes and the right extinguishing methods with Guard-X Protection incendie, fire safety experts in Greater Montreal.
Did you know that a grease fire can’t be extinguished like a wood fire? Or that a paint-related fire requires a very different approach from one involving industrial metals?
The reason is simple: there are multiple classes of fires, and each requires a specific extinguishing method.
At Guard-X, a fire safety leader in Greater Montreal, your protection is our priority. Here’s an overview of the 5 fire classes and how to handle them safely.
The 5 Main Classes of Fire
Class A – Solid Combustibles
Wood, paper, fabric, plastic... These fires go through two phases:
- Smoldering (no flame): A “hidden” fire that can remain unnoticed
- Open flame combustion: Often triggered by a simple draft of air
Class B – Flammable Liquids
Gasoline, solvents, varnish, cooking grease... These fires either burn or don’t—no smoldering. To extinguish them, you must eliminate the flames.
Class C – Energized Electrical Fires
Electrical panels, appliances, motors... High risk of electrocution. Never intervene unless you are professionally trained.
Class D – Combustible Metals
Magnesium, sodium, aluminum, metallic dust... Extremely intense and bright fires, typically found in industrial environments.
Class K – Cooking Oils and Grease
Typical in commercial kitchens, caused by overheated oils or fats. Never use water! Special extinguishing agents are required.
The Right Extinguisher for Each Type of Fire
- Water: For Class A fires only. Never use on electrical, grease, or metal fires.
- Dry Chemical Powder: Interrupts chemical reactions; suitable for Classes A, B, and C.
- Foam: Typically used by firefighters; effective for Class B fires.
- CO2 (Carbon Dioxide): Smothers the fire; ideal for Classes B and C.
- Special Agents: Required for Class D and K fires; includes compounds like ammonium acetate.
Always check the label on the extinguisher—it clearly indicates the fire classes it can handle.
Extreme Caution with Class D and K Fires
- Metal Fires (Class D): Some metals may explode on contact with water or ignite spontaneously. Only trained firefighters using specialized powder extinguishers should respond.
• Kitchen Fires (Class K): Require agents that form a sealing film over burning oil. Never use water—it can cause a violent flare-up.
How to Use a Fire Extinguisher: The PASS Technique
If the fire is small and manageable, use the PASS method from a distance of at least 10 feet (3 meters):
- P: Pull the pin
- A: Aim the nozzle at the base of the flames
- S: Squeeze the handle to release the agent
- S: Sweep from side to side until the fire is out
If the fire is too large to control: evacuate immediately and call 911.
Guard-X: The Right Extinguisher, in the Right Place
Our experts will help you choose the appropriate extinguisher based on the specific risks in your home, workplace, or industrial facility.