Essentials of Fire Fighting (4th Edition)
Chapter 2 Terms
Fire Behavior
Arcing
Luminous discharge that is formed when a current jumps a gap in a circuit or between 2 electrodes.
Backdraft
Instantaneous explosion or rapid burning of superheated gases that occurs when oxygen is introduced into an oxygen-depleted confined space. It may occur because of inadequate or improper ventilation procedures.
Boiling Point
Temperature of a substance when the vapor pressure exceeds atmospheric pressure. At this temperature, the rate of evaporation exceeds the rate of condensation. At this point, more liquid is turning into gas than gas is turning back into a liquid.
Compartment
One of the parts or spaces into which an area is subdivided.
Flammable Limit
Percentage of a substance in air that will burn once it is ignited. Most substances have an upper (too rich) and lower (too lean) flammable limit. Also called Explosive Limit and FlammableRange.
Flash Point
Minimum temperature at which a liquid gives off enough vapors to form an ignitable mixture with air near the liquid's surface.
Halon
Halogenated agent; extinguishes fire by inhibiting the chemical reaction between fuel and oxygen.
Heat Of Combustion
Amount of heat generated by the combustion (oxidation) reaction.
Heat Of Compression
Amount of heat generated by the the expansion of gases within an enclosed space.
Hydrocarbons
Organic compound containing only hydrogen and carbon and found primarily in petroleum products and coal.
Ignition Temperature
Minimum temperature to which a fuel in air must be heated in order to start self-sustained combustion independent of the heating source.
Nonpolar Solvent
Liquids that do not mix readily with water.
Oxidizer
Substance that yields oxygen readily and may stimulate the combustion of organic and inorganic matter.
Polar Solvents
Liquids that mix readily with water.
Self Oxidizing
Ability of a substance to supply its own supply of oxygen.
Static Electricity
Accumulation of electrical charges on opposing surfaces created by the separation of unlike materials or by the movement of surfaces.
Thermal Layering
(1) Tendency of gases to form into layers, according to temperature. (2) Process of burning in a confined space in which the hottest air is found at the ceiling and the coolest air at floor level.
Vaporization
Passage from a liquid to a gaseous state. Rate of vaporization depends on the substance involved, heat, and pressure.
Ventilation
Systematic removal of heated air, smoke, and/or gases from a structure and replacing them with cooler and/or fresher air to reduce damage and to facilitate fire fighting operations.
Wet Water
Wetting agent that is introduced to water to reduce the surface tension and improve its penetration qualities.