What is combustion?
- All fires are the result of a chemical reaction known as combustion
- Combustion is the reaction of a fuel with oxygen
What is an exothermic reaction?
A chemical reaction that releases energy -> all combustion reactions are exothermic
What is an endothermic reaction?
A reaction that requires the input of energy -> all chemical reactions require an input of energy to get them started, called activation energy
What are the 4 elements necessary for a fire to take place?
A source of heat, fuel, oxygen and a chain reaction between the fuel and oxygen
What is the flash point?
The lowest temperature that will allow a liquid to produce a flammable vapour
What is a flashback?
When oxygen is limited and then sudden ventilation occurs, this increased oxygen will cause an explosive fire
What is an accelerant?
- Fuels that are easily vaporised and support combustion that are highly exothermic
- Burn easily and the energy they emit provides the activation energy needed for combustion
- Often leave a residue behind
- e.g. gasoline, kerosene, charcoal lighters
What are the three types of fires?
Natural, accidental and deliberate
What is an incendiary fire?
A fire that is deliberately set
What is an arson fire?
A fire that is deliberately set with criminal intent
How are deliberate fires identified?
- Accidental and natural causes are eliminated
- Residues from an accelerant
- Multiple points of origin
