Not all fires are the same – some burn faster and are more dangerous, and most importantly, not all fires can be put out or suppressed the same way. Understanding the different types of fire classes can help determine how to best prepare in case of a fire emergency.
Fire is divided into five classes (A, B, C, D, and K) that are primarily based on the fuel that is burning. This classification system helps to assess hazards and determine the most effective type of extinguishing agent.
Class A Fires
The most common class, these fires involve common combustibles such as wood, paper, cloth, rubber, trash, and plastics.
Class B Fires
These Involve flammable liquids, solvents, oil, gasoline, propane, butane, paints, lacquers, and other oil-based products or petroleum-based products.
Class C Fires
Old wiring and space heaters are common causes for residential Class C fires, which involve energized electrical equipment such as wiring, controls, motors, machinery, or appliances.
Class D Fires
While Class D isn’t as common, they can be more difficult to extinguish. They typically involve combustible metals such as magnesium, lithium, potassium, and titanium. This type of fire is more commonly seen in laboratories.
Class K Fires
While Class K fires also involve flammable liquids, these are related to combustible cooking materials such as oils and grease commonly found in kitchens. Class K fires can spread quickly and be the most difficult to manage, especially since water can make the situation worse.
Choosing the right type of fire extinguisher for a corresponding fire class is essential when preparing for a fire emergency. Here’s how to suppress different types of fire classes:
| Fire Class | How to Suppress | Fire Extinguisher |
| Class A | Water or Smother | Water, Foam, ABC Dry Chemical, Halotron |
| Class B | Smother | CO2, Halotron, ABC dry chemical, BC dry chemical, Purple K, Foam |
| Class C | Non-conductive chemical | ABC dry chemical, BC dry chemical, Purple K, CO2, Halotron |
| Class D | Dry powder agents | Dry Powder |
| Class K | Smother, Wet chemical | Wet Chemical |
