Basic Firefighter 1 questions with complete answers

Basic Firefighter 1 questions with complete answers Three (3) Physical State of Matter in which FUEL EXISTS. 1. Solids 2. Liquids 3. Gases Three (3) ways HEAT is transfered 1. Conduction 2. Convection 3. Radiation Heat Transferred by an intervening Heat-conducting medium or by the direct contact of two bodies CONDUCTION Note: Not all materials conduct heat similarly. Four (4) products of combustion 1. Heat 2. Smoke 3. Gases 4. Light (Flame) Three (3) MAIN progressive phases or stages of a Fire 1. Incipient (or beginning) Phase 2. Steady-State Burning (or Free burning) Phase 3. Hot-Smoldering Phase Characteristics of liquid fuels which increases Difficulty of Extinguishment Liquids Assume the shape of their container. Heat transferred by the movement of air, other gases or liquids. FORM OF HEAT TRANSFER Convection Note: Heat transferred by convection usually occurs in an upward direction. The Four (4) elements of the Fire Tetrahedron 1. Fuel (Reducing Agent) 2. Oxygen (Oxidizing Agent) 3. Heat (Temperature) 4. Chemical Chain Reaction Mode of Combustion Associated with the Fire Triangle Smoldering Mode of Combustion Occurs when unburned combustible gases which accumulate at the ceiling level are pushed into uninvolved areas where they mix with oxygen and upon reaching their flammable range, ignite and expand rapidly rolling over the ceiling. Rollover Note: unlike a Flashover, in a Rollover only the gases are burning, not the contents of the room. Four (4) methods used to extinguish fire. 1. Elimination of Fuel 2. Exclusion of Oxygen 3. Reduction of Temperature 4. Inhibition of the Chemical Chain Reaction Mode of combustion associated with the fire tetrahedron Flaming Mode of Combustion Terms for process by which gases evolve from solid fuels when they are heated and for processes by which gases evolve from liquid fuels. Solid Fuels - Pyrolysis Liquid Fuels - Vaporization Density of gases in relation to air Vapor Density The Vapor Density of Air is 1 Gas which supports combustion Oxygen Fire phase when portable fire extinguishers may be most effective Incipient Phase Caused by an excessive buildup of heat, flames fully involve and entire area or surface Flashover Definition of Combustion The self-sustaining process of rapid oxidation of a fuel producing light and heat. Involves flammable liquids, greases and gasses CLASSIFICATION OF FIRE Class B Note: Oxygen exclusion is the most effective way to control Class B fires. Percentage of Oxygen in room air and percentage required for combustion and life safety There is 21% Oxygen in room air. Oxygen concentrations below 15% will not support combustion. Oxygen concentrations below 17% present a life safety hazard. The three (3) elements of the fire triangle 1. Fuel (Reducing agent) 2. Oxygen (Oxidizing agent) 3. Heat (Temperature) Includes ordinary combustibles such as wood, paper, cloth, plastic and rubber. CLASSIFICATION OF FIRE Class A Note: Water is the most common agent used to control Class A fires. Heat waves travel where matter does not exist, hit and object and heat it. FORM OF HEAT TRANSFER Radiation Note: Radiated heat is a major cause of fire spread to exposures. Protection of exposures demands early attention. Concentration range within which a mixture of fuel vapor and air will burn when ignited Flammable Range Note: individual fuels have different flammable ranges. Involves Energized electrical equipment CLASSIFICATION OF FIRE Class C Note- A non-conducting extinguishing agent should be used if equipment is still energized Involves combustible metals including magnesium, sodium and potassium CLASSIFICATION OF FIRE Class D Note - There is no single extinguishing agent available that will effectively control all Class D fires. Classes of Fire extinguishers to which numerical ratings are not assigned. Class C and D Density of liquids in relation of water Specific Gravity The specific gravity of water is 1 Symbol associated with a Class C fire extinguisher designation Blue Circle Symbol associated with a Class D fire extinguisher Yellow Star Symbol associated with a Class A fire extinguisher Green Triangle Symbol associated with a Class B fire extinguisher Red Square Significance of the rating on a Class A fire extinguisher The rating corresponds to a given amount of water. Multiply the rating number by 1-1/4 gallons of water. Position in which fire extinguishers should be carrier and operated Upright Types of fire best extinguished by Halon fire extinguishers Primarily Class B and Class C fires, but also effective on some class A fires Way in which the nozzles of most AFFF fire extinguishers differ from those of standard extinguishers They are designed to introduce air into the steam. Significance of the rating number on a Class B extinguisher The rating number corresponds to the number of square feet of deep-layer flammable liquid fire that can be extinguished by a non-expert operator Length of time between hydrostatic tests of fire extinguishers Stored-pressure water or carbon dioxide extinguisher Five (5) years Dry Chemical - twelve (12) years Four (4) general steps for operating portable fire extinguishers 1. Pull the safety pin 2. Aim the nozzle or outlet toward the fire 3. Squeeze the handle to discharge the agent 4. Sweep the agent back and forth at the base of the flames