Humberside Fire and Rescue Service

Unit 22

Unit 22 - The Science of fire and extinction

Unit abstract

This unit will provide learners with an introduction to the science of fire and methods of extinction by examining the fundamentals of fire, its behaviour and development (ignition, growth and spread). It also covers the varied extinguishing media and the correct identification and application of those media for given types of fire.

Knowledge gained through completion of this unit will enable learners to understand how to recognise the potential for fire to occur, how to respond to a fire when it does occur, the resulting products from fire and which extinguishing media are best suited to a variety of fire situations.

This will be achieved through participation in a variety of different activities; which will culminate in learners having the ability to demonstrate a broad range of knowledge and understanding of the science of fire and its extinction.

Learning outcomes

On completion of this unit a learner should:

  • Understand the science of fire
  • Be able to describe methods of fire extinction and appropriate extinguishing media

1 Understand the science of fire

Fire and combustion: Chemical processes of ignition, combustion and development of fire, the triangle of fire; Products of fire, light, heat and smoke; controlled burning e.g. a campfire, stove, uncontrolled burning e.g. in buildings or in the open; oxygen, heat and fuel, ignition sources

Fire Behaviour and fire development: conduction, convection and radiation; rate of fire spread, flashover, backdraught

Types of fires: Classification of fires i.e.; Class A - fires involving carbonaceous materials e.g. wood, paper; Class B - fires involving liquids or liquefiable solids; Class C - fires involving gases; Class D - fires involving metals and Class F – liquid fires.

2 Be able to describe methods of fire extinction and applicable extinguishing media

Removal of heat (Cooling): Limiting temperature e.g. application of a jet or spray of water, steam

Removal of fuel (Starvation – limiting fuel): Removing potential fuel from the neighbourhood of a fire, creating fire breaks, cutting off gas supply, Removing the fire from the mass of combustible material e.g. pulling apart a haystack or thatched roof, beating out of fires

Removal or limitation of oxygen (smothering or blanketing): Limiting oxygen e.g. fire blanket, closing doors and windows, snuffing out a candle, placing a lid on a hot fat pan, turning off ventilation

Extinguishing media: Water; ‘inert gases’; foam; vaporising liquids; carbon dioxide and; dry chemical powders

Grading Grid

In order to pass this unit, the evidence that the learner presents for assessment needs to demonstrate that they can meet all of the learning outcomes for the unit. The criteria for a pass grade describe the level of achievement required to pass this unit.

Grading criteria
To achieve a pass grade the evidence must show that the learner is able to:
P1Be able to explain the three components and provide examples of the three components in relation to the triangle of fire, providing one example of each component
P2Know the different methods of extinguishing a fire providing one example for each side of the triangle of fire.
P3Identify two fire extinguishing media and provide an example for each of where they should and should not be used to extinguish fire

Developing Independence and Leadership...

Use the links below to quickly jump to any unit within in the Edexcel Level 2 BTEC Award, Certificate and Diploma in Fire and Rescue Services in the Community.

Essential Resources

Fire Service Manuals/Circulars:

  • Fire Services Youth Training Association-Fire and Rescue Service Manual Youth Training and Development (Stationary Office, 31st August 2004) ISBN10- 0113412932
  • Related Fire Services Circulars and where these have been superseded consideration should be given to these documents within your organisation.
Partnership Authorities