What are Classes of Fire?

In short classes of fire refers to the fuel (What) that is burning. The key is to know with what kind of fire you are dealing with to extinguish it correctly. By now we all agree that a fire is a self-sustained chemical reaction that requires fuel; heat and oxygen that gives off energy and products of combustion.

To be able to burn, fuels need to be in a gaseous state. Combustible material and gases are released when solid fuels are heated. In other words: your braai wood will only burn if enough flammable gasses are released due to heat.

Bellow I have listed what each Class Fire is:

Class A fire involves combustible material such as wood; paper; rubber and plastics. Flammable gasses released by decomposition. (pyrolysis) – The fire extinguisher best to use is a Dry Chemical Powder (DCP)

Class B fire involve flammable and combustible liquids and gasses. These are the most dangerous class of fire because they are already in the state required for ignition. Fuels like diesel; petrol; thinners; sanitizers and LPG.  – The correct fire extinguisher to use is an Aqueous Film Forming Foam (AFFF)

Class C fire involves energized electrical equipment such as computers; appliances; transformers and solar systems. – The best fire extinguisher to use is a Carbon Dioxide (CO2)

Class D fire involves combustible metals like aluminum and titanium. – The fire extinguisher to use is a Purple K.

Class F fire involves cooking oils and fats used in kitchens. – The fire extinguisher best to use is a Fry Fighter

Make sure you have the correct equipment to deal with the class of fire that pose a risk to your business.

Albert Smit

NOSA Safety officer