By: Dirk Patrick Cloete Fire Behavior By: Dirk Patrick Cloete

The importance of knowledge of fire behavior for a firefighter? Firefighters need to have an understanding of fire behavior that permits them to recognize developing fire conditions and be able to respond safely and effectively to mitigate the hazards presented by the fire environment.

Do you still remember the different classification of fires? DISCUSSION QUESTION Do you still remember the different classification of fires?

Class A Fires Involve ordinary combustible materials

Class B Fires Involve flammable and combustible liquids and gases

Class C Fires Involve energized electrical equipment Typical sources — Household appliances, computers, electric motors

Class D Fires Involve combustible metals

Class K Fires Involve oils and greases Require extinguishing agent specifically formulated for materials involved

Lesson Objectives: Upon successful completion of this lesson, the student shall be able to: Describe methods used to control and extinguish different types of fires

Temperature Reduction One of the most common methods of fire control/extinguishment Depends on reducing temperature of fuel to point of insufficient vapor to burn Solid fuels, liquid fuels with high flash points can be extinguished by cooling

Temperature Reduction Use of water is most effective method for extinguishment of smoldering fires. Enough water must be applied to absorb heat generated by combustion. Cooling with water cannot reduce vapor production enough to extinguish fires in low flash point flammable liquids/gases

Fuel Removal Effectively extinguishes any fire Simplest method is to allow a fire to burn until all fuel consumed.

Oxygen Exclusion Reduces fire’s growth and may totally extinguish over time Limiting fire’s air supply can be highly effective fire control action.

Chemical Flame Inhibition Extinguishing agents interrupt combustion reaction, stop flame production Effective on gas, liquid fuels because they must flame to burn Does not easily extinguish surface mode fires

Summary Firefighters need to understand the combustion process and how fire behaves in different materials/different environments. They also need to know how fires are classified so that they can select and apply the most appropriate extinguishing agent.

How can fires be controlled and extinguished? DISCUSSION QUESTION How can fires be controlled and extinguished?

DISCUSSION QUESTION Match the different classes of fire with the type of extinguishing method that will control or extinguish it

For next time read up on the phenomena known as Backdraft