FDNY PROBIE MANUAL CHAPTER 1 CHEMISTRY OF FIRE WITH COMPLETE SOLUTIONS ALREADY GRADED A+|GUARANTEED SUCCESS

Flammable Limit The percentage of a substance that needs to exist in air that will burn once ignited Flash Point Temperature where liquid fuels give off enough vapors to ignite, but not enough to burn Heat Form of energy that raises temperature measured by amount of work it does. Ignition Temperature Minimum heat that a fuel in air must be heated to start a self-sustained combustion without a seperate ignition source Conduction Movement of Heat from one body to another via direct contact. EG Metal touches Metal Convection Movement of heat by movement of air or liquid Usually transfers up Radiation Movement of heat via Infrared waves. EG the heat from the sun reaches us. Fire Tetrahedron Temperature, Oxidizing agent, reducing agent, AND A self sustained chemical reaction Pyrolysis Chemical decomposition of a solid fuel. EG gases emit from wood when burned. Vaporization Process of turning liquid fuel into Gas. Oxygen required to Sustain Burn 16% Oxygen in air 21% Incipient Phase First phase of a fire, fire is contained to original materials fire still producing water vapor. Steady-State Burning Phase The Flame Spread phase fire has sufficient oxygen and fuel and fire is spreading Hot Smoldering Phase After Steady-State burning where fire can no longer be sustained heavy smoke, and high temperatures. Rollover When gases from the incipient fire reach the ceiling and mushroom out mix with oxygen and ignite Flashover Spontaneous combustion of everything in the area due to super high temperatures. Backdraft When oxygen is introduced to a fire that is in the smoldering phase. This may cause an explosion. Thermal Layering The natural layering of different gases at different temperatures in a confined space. Disturbing this can cause dangerous conditions for firefighters. What is in Smoke? Carbon Monoxide, Carbon Dioxide, Nitrogen, Oxygen, Carbon Particles, Misc. Byproducts Potential Backdraft Characterisitics Pressurized smoke exiting, Smoke becoming Grey/yellow, Confinement, Excessive heat, Small or no flame, Smoke Stained windows, Muffled sounds, Rapid movement of air Class A Fires Combustibles Class B Fires Liquids/ Fuels Class C Fires Electrical Fires Class D Fires Metal Fires EG Magnesium