CHEMISTRY OF FIRE

• Fire is a type of oxidation
• Ignition temperature is the minimum temperature needed to spontaneously ignite fuel
• Heat of combustion is the heat evolved when a substance burns
• The speed at which oxidation takes place is needed to investigate fires
• Glowing combustion is burning at the fuel if interface
• Spontaneous combustion is rare and takes place in poorly ventilated areas
• Fuel, oxygen, and heat must be present to create a combustion

SEARCHING THE FIRE SCENE

• Arson investigator examines scene as soon as fire is extinguished
• Most arson fires are started with petroleum based accelerants
• The fire's origin is important to find when searching for hints of origin
• Signs of arson include separate fires and severe burning of the floor

COLLECTION/Preservation of Evidence

• Vapor detectors locate liquid residues
• Control specimens must be collected
• Igniters such as matches or sparking devices must be conducted
• Fuel must be present if a combustion is sustained

ANALYSIS OF FLAMMABLE RESIDUES

• Gas chromatograph separates the hydrocarbon components
• Comparing chromatographic peaks from a fire scene, a forensic analyst may be able to identify the accelerant

LACY YONKERS