Understanding the “Triangle of Fire”

There are three variables necessary for a fire to light and keep burning: fuel (flammable liquids, solids or gas), heat and air, which make up the “Triangle of Fire”. The only way to effectively extinguish a fire is to permanently remove one of these elements – by starving the source, smothering the flames or cooling the area.

Chubb Fire and Security South Africa fire products consultant, Steve Bastuba, explains how to determine which element of the triangle needs to be eliminated. He says:

“The respondent must establish the type of fire which is posing a threat. Fires are categorised from Class A to Class F, depending on the fuel source:
Class A fires involve solid and organic materials, such as wood.
Class B fires involve flammable liquids and flammable gases.
Class C fires result from the malfunction of energised electrical equipment.
Class D fires occur on combustible metals.
And Class F fires involve fat and cooking oil in kitchen applications.” 

Selecting the correct fire extinguisher to manage the triangle
In residential environments, general purpose dry powder extinguishers (rated for class ABC fires) are sufficient. However, if large-scale cooking takes place in the home, a class F extinguisher is also recommended.

In commercial environments, the type of extinguisher needed depends on the type of business. If there is an electrical fire hazard posed by printers or heaters, for example, a dry powder extinguisher is advisable.

“In a server room, a fully installed gas suppression system such as Argonite is ideal, as it smothers the fire to ensure that valuable equipment is not damaged,” adds Bastuba.

The following colour-coded labels are used to identify extinguishers in South Africa:
•    Blue: Dry powder general purpose extinguisher
•    Black: Carbon dioxide extinguisher   
•    Red: Water extinguisher
•    Light Tan/Fawn: Foam extinguisher
•    Yellow: Wet chemical

In addition to extinguishers, fire protection equipment includes fire hose reels and hydrants. Bastuba says that all equipment must be painted red and be SABS approved. “Manufacturers and installers of these products and systems are required by law to be registered with the SABS and all products should carry the SABS mark.”