072: Fire classes and basic principles of the fire

Unfortunately, we do not take the possibility of fire around us seriously and therefore do not prepare ourselves for it. One of the necessities of life and work is to get acquainted with the basic principles of fire. We are all more or less familiar with the fire triangle or fire square:

1. Heat
2. Fuel
3. Oxygen (Oxidizing agent)
4. Chemical reaction

We can put out the fire by removing even one of these four ingredients.

A fire classes are categorising the fire according to type of materials and used to determine the suitable extinguishing agent for each category. Type of materials are classified according to different standards in Europe, USA and Australia.

According to European Standard (EN2) we have below fire types:

1. Class A: Combustible materials   (e.g. paper, wood, cloth/fabric, plastic, refuse)
2. Class B: Flammable liquids   (e.g. paint, gasoline, kerosene, grease, oil)
3. Class C: Flammable gases   (e.g. butane, propane, methane)
4. Class D: Flammable metals   (e.g. alkali metals such as lithium and potassium, alkaline earth metals such as magnesium, titanium, zirconium)
5. Class E: Electrical fire   (e.g. kitchen appliances, motor, transformer, wiring, circuit breaker, outlet)
6. Class F: Cooking oils and fats   (e.g. greases, vegetable fats, animal fats)

Note1: Fire extinguisher agents must be selected according to fire classes. Using the extinguisher with the wrong class may cause the spread of fire or even injuries and death.

Note2: For fires with combination of materials with different fire classes, ABC extinguishers should be selected.