BCOT - Fire Safety Questions and Answers 2023

BCOT - Fire Safety Questions and Answers 2023 in case of fire Sound the alarm (location & how to activate) MUST Call Main Control Calling Main Control for Fire Procedures Give your name Location of fire Type of fire Hold phone for verification The fire triangle oxygen - right side heat -bottom fuel - left side Fire Tetrahedron fuel -top triangle chemical chain reaction -bottom triangle heat- bottom left triangle oxygen - bottom right triangle Chemical Chain reaction in the burning process of fuel elements( compounds)are released by heat produced by the fire. These elements join in the fire (combined with oxygen) to produce more heat which releases more fuel elements What is the difference between the fire triangle and the fire tetrahedron? Chemical chain reaction Oxygen percentage in normal air 21% Oxygen supports combustion & life Minimum percentage of oxygen needed to support respiration & combustion 16% visible flame goes out (oxygen) 15% Fire goes out (oxygen) 5% definition of fire fire is a rapid chemical combination of fuel and oxygen in the presence of Heat usually accompanied by production of heat light and combustion byproducts (smoke gases and dust) byproducts of combustion smoke gases and dust Fire is usually accompanied by smoke gases and dust solid states of fuel -tetrahedron wood, paper, plastic, rubber converted into a gas by pyrolysis size and shape effects ease of ignition and rate of burning liquid states of fuel gasoline, kerosene, paint thinner, vaporization produces gas flammable or combustible flammable - vaporization occurs at 99 degrees and below combustible - vaporization occurs at 100 degrees and above Gas State of fuel natural gas LP gas, acetyline, no conversion necessary heat a form of energy that raises temperature. Heat is measured by the amount of work it does ,for example; the amount of heat needed to make a column of mercury expand inside a glass thermometer four sources of heat energy chemical heat energy electrical heat energy mechanical heat energy nuclear heat energy class a ordinary combustibles class b liquid class c energized electrical class d metals heat transfer important because heat is the essential for a fire to be initiated and combustion to occur. Heat is transferred in one of three ways Conduction the transfer of heat through a heat conducting medium *pipes *steel roof beams convection heat transferred through the movement of hot air or liquid *usually vertically (heat rises) * includes direct flame contact radiation movement of heat waves through space until they strike a solid object *movement is in all directions *similar to the sun *unaffected by wind products of combustible *flame *heat *smoke *Fire gases four phases of burning *ignition *growth *fully developed *decay Ignition phase * oxygen 21% *temperature slightly elevated -100 degrees *easy to extinguish growth phase *Oxygen is above 15% *room temperature up to 1300 degrees *Fire spreads rapidly *flashover possible rollover or flameover a fire condition that takes place when unburned combustible glasses released during the incipient stage, which of collected at the ceiling, ignite and a fire front develops and expands very rapidly across the ceiling flashover occurs between the growth and fully developed phases of the fire. This condition occurs when the room or the other area becomes heated to a point that all contents of the room reach their ignition temperature and ignite simultaneously best method of preventing Backdraft proper ventilation fully developed phase *all combustibles have ignited & heat is being produced at the maximum rate. the fire has everything it needs & produces large amounts of fire gases. *everything has ignited *temperature is over 3000 degrees decay phase *the Fire is running out of fuel and oxygen. the atmosphere is still hot and heat energy is still being released. *the rate of combustion is slowing down. the intensity of the fire decreases to the point where there is only smoldering fuel. *high room temperature *little or no flame *potential for backdraft *most dangerous phase of fire