A fire extinguisher can be used to fight small fires before they grow to become life-threatening. However, using the wrong type of fire extinguisher can actually make a fire worse. Here is what you need to know to purchase the correct extinguisher and keep yourself safe from harm. 

Fire Classification
Class A: Fires caused by ordinary combustibles such as wood, paper, cloth, rubber, and plastics.
Class B: Fires caused by flammable liquids like gasoline, oil, and solvents.
Class C: Persistent fires started by energized electrical equipment like appliances, tools, and computers (Electrical Fires).
Class D: Fires involving combustible metals like magnesium, titanium, and sodium. These may require specialized extinguishing agents specific to the metal.
Class K: Specifically for fires in commercial kitchens involving cooking oils and fats.

Fire Extinguisher Types
Water: Effective for class A fires. Water types cool down and smother fires until they are extinguished.
Foam: Effective for class A and B fires. These types discharge a foam that cuts off the fire’s oxygen supply while absorbing heat.
Carbon Dioxide: Effective for class B and C fires. CO₂ displaces oxygen, extinguishing the fire without damaging expensive equipment.
Dry Chemical: Effective for class A,B, and C fires. Smothers the fire, separating it from oxygen and absorbing heat.
Wet Chemical: Effective for class A and K fires. A fine mist of solution cools the fire and forms a foam coating to prevent re-ignition.
Dry Powder: Effective for class D fires. These types are intended for use on class D fires and for specific metals.
Clean Agent: Effective for class B and C fires. Absorbs heat, and cuts off the fire’s oxygen supply.

Size / Capacity
Portable Fire Extinguishers: Smaller, handheld units designed for individual use. (e.g. 2.5lb, 5lb, 10lb)
Wheeled Fire Extinguishers: Larger units mounted on wheels for easier transport to the fire location, often used in industrial or high-hazard areas.