Fire Service Ventilation (7th Edition)
Chapter 1-Fire Behavior/Airflow Characteristics
Test Review

• The three phases of fire are: Incipient, Steady-state, and Hot-smoldering.
• The incipient phase begins with the actual ignition and is usually limited to the original products of ignition.
• The supply of oxygen has been depleted in the hot-smoldering phase.
• Opening a window may be all that is required to ventilate during the incipient phase.
• Ventilation on the side opposite the fire attack can reduce rollover potential.
• Directing water toward the ceiling and room contents along with aggressive ventilation can reduce flashover potential.
• Opening a door or window late in the hot-smoldering phase can cause a backdraft.
• Warning signs of backdraft include:  Smoke exiting small openings under pressure, black smoke becoming dense, grayish-yellow, confinement, excessive heat, little or no visible flame, smoke leaving structure at intervals, muffled sounds, or sudden rapid movement of air inward when an opening is made.
• Warning signs of backdraft from inside the structure include:  windows rattling, flames becoming sickly yellow or less lively, muffled noises, and fire diminishing before water is applied.
• If backdraft conditions are developing, leave as quickly as possible, if not possible, stay low and away from ventilation openings.
• Carbon monoxide is present in every fire.
• Temperature is an indicator of heat.
• The greater the molecular activity, the more intense the heat and the higher the temperature.
• The Law of Heat Flow states that "heat tends to flow from a warmer to a colder substance" and "the colder of the two bodies will absorb heat until both objects are the same temperature".
• Asbestos is a carcinogen and is extremely dangerous when airborne.
• Nitrogen oxides are liberated in the combustion of pyroxylin plastics.
• Phosgene is a strong lung irritant.
• Carbon monoxide is an asphyxiates by combining with hemoglobin 200 times more readily than does oxygen.
• Particulates in smoke include:  carbon, tar, dust, and fire gases.
• Most gases emitted by fire have a vapor density greater than 1.0.
• Fire gases return to ground level after a fire, making it important to wear SCBA during overhaul.
• The factors that determine the fire gases given off are:  nature of the combustible, rate of heating, temperature of evolved gases, and oxygen concentration.
• Acrolein is a strong respiratory irritant produced when polyethylene, wood, and natural materials smolder.
• Acrolein is used in the manufacture of pharmaceuticals, herbicides, and tear gas.
• Carbon dioxide is a colorless, odorless, nonflammable gas produces in free-burning fires.
• Carbon dioxide can asphyxiate by excluding oxygen from a space as well as increase inhalation of toxic gases by increasing respirations.
• Carbon monoxide is a colorless, tasteless, odorless gas present in every fire.
• The darker smoke is, the more carbon monoxide being produced.
• Carbon monoxide combines 200 times more readily than oxygen to hemoglobin, resulting in inadequate oxygen perfusion.
• Hydrogen chloride is a colorless, very pungent, irritating gas produces when plastics, containing chlorine, burn.
• Hydrogen cyanide is a colorless gas with an almond odor that is 20 times more toxic than carbon monoxide.
• Hydrogen cyanide is an asphyxiant that is skin absorbable.
• Wool, silk, and nitrogen-containing products give off hydrogen cyanide when they burn.
• Nitric oxides, which are reddish brown or copper color, are liberated from burning pyroxylin plastics.
• Nitric oxides convert to nitrogen dioxide in the presence of oxygen, which is a pulmonary irritant.
• Phosgene is a highly toxic, colorless gas with a odor of musty hay.
• When freon contacts flame, it produces phosgene gas that is a strong lung irritant.
• The process of gases rising until they reach the top of a space, spreading out laterally, then banking down is termed mushrooming.
• A pressure differential is a low pressure area at the bottom of a space created by the upflow of fire gases.
• Horizontal layers of different temperature levels within a space is termed thermal layering.
• An inversion is when smoke rises until the temperature of the air equals the smoke temperature, then spreads out laterally in a horizontal layer.
• Sulfur dioxide, large quantities of carbon dioxide, and oxygen-deficient atmospheres are hazardous non-fire gases found in most communities.
• Methane, hydrogen, and acetylene are lighter-than-air gases.
• Chlorine, and carbon dioxide are heavier-than-air gases.
• Pressure transfers from an area of higher pressure to areas of lower pressure until pressures equalize.
• Neutral pressure planes are points within structures, usually midpoint vertically, in which the pressure of internal and external spaces are equal.
• The stack effect is the inward pull of air at the bottom of a space due to negative pressure which is created by convected smoke and heat to upper portions which creates a positive pressure at the top of the space.
• Dilution rate is affected by volume of air moved, placement of fan (if used), size of openings, and availability of replacement air.