Ch6 Flashcards
___Is a developed skill that helps you predict fire behavior
Reading smoke
Smoke leaving a structure has four key attributes:
Volume, velocity (pressure), density, and color
_______often leads to combustion
Pyrolysis
Surfaces that are smoking, not burning, are ___________.
Off aggregating
_______Are the more prevalent solids in smoke
Soot and ash
___Is Carbon, (officially carbon black) and Carbon can support flaming
Soot
The trace metals and minerals, depleted salts, that can no longer support flame
Ash
From most interior fires, the volumetric composition of smoke is mostly________.
Particulate matter
An _______can be defined as a suspended or propelled liquid
Aerosol
Hydrocarbons give smoke a____color
Satin wet black
Some very common hydrocarbons in smoke can self-ignite as low as 450°F, but they often do not ignite because the particulates have made the smoke too rich to burn. This makes smoke a typical house fire_________.
Amazingly explosive
Smoke is ignitable as low as___and has a collective flammable range of_to_in air!
450F
1-74%
Self ignition temperature of carbon monoxide
1128°F
Self ignition temperature of hydrogen cyanide
1000°F
Self ignition temperature of benzene
928°F
Self ignition temperature of Acrolein
450°F
Two triggers may cause accumulated smoke to ignite :
The right temperature and the right mixture
Smoke gases that are below their ignition temperature but above flashpoint need only a proper air mix and a sudden spark or flame to complete their ignition, called a_____ignition
Piloted
The ignition of smoke that has pressurized a room or box likely result in an __________
Explosive surge
The ISO who watches what the smoke is doing makes better decisions than the one focused on flaming, because the smoke tells you how intense the fire is about to become as opposed to how bad it currently is
Key sentence
The avenues that heat, smoke, flames, and combustion air follow
Flow paths
A compartmentalized fire condition where open flaming decreases because smoke production displaces and limits available combustion air, although heating continues to produce smoke
Ventilation-limited phase
*introduction of air will cause the fire to rapidly transition into an explosive growth phase
A rapidfire growth phenomenon that occurs when combustion air is reintroduced into a ventilation controlled fire, leading to smoke flame over and room flashovers
Explosive growth phase
A proactive solution to prevent the explosive growth phase includes_____, which is the application of water to ceilings and walls to help quench and cool moving smoke
Protective cooling
Some call this the fuel limited phase.
Decay phase
A hostile event warning sign and is characterized as the intermittent ignition of small pockets of smoke, usually seen as fingers of flame that dance through the upper smoke Layer
Ghosting
Ghosting is not necessarily a hostile our event but serves as a warning sign of impending?
Flashover or flame over
A hostile fire event that includes the ignition insisting burning of the overhead smoke a layer within a room and/or hallway
Flame over
A hostile fire event that occurs when a spark or flame is introduced into a pocket of smoke that is below ignition temperature but above some aggregate flashpoint
Smoke explosion
Smoke flame over upon the breaking of windows or opening of the doors is a late sign of?
Explosive growth phase
Exhaust flow paths that intermittently puff or try to suck air, open doors and windows
Explosive growth phase
The explosive growth event, flame over and delayed flashover, is triggered by a volume shift between smoke in the air that occurs over a_to_time span
10 to 90 seconds
The ______event will ignite more like a detonation, burning above the speed of sound, and will likely include a shockwave.
Backdraft
A dangerously late warning sign of flashover
Sensation of heat
Sets the stage for understanding the amount of fuels that are offgassing in a given space
Volume
Can create an impression of the fire relative to the size of the space it fills
Volume of smoke
An indicator of pressure that has built up in the building
Velocity
From a practical fire behavior point of view, two forces cause smoke to pressurize in a building:
Convection heat or smoke volume
Turbulence smoke is caused by____
Serious heat
Smoke that is being developed by pyrolysis begins____
Laminar
Turbulent smoke as filled a compartment is a warning sign of?
Impending flashover
The most important smoke observation is whether it’s velocity is?
Turbulent or laminar
*previous TQ
The smoke velocity you see outside the building is ultimately determined by?
The size and restrictiveness of the exhaust opening
Comparing the velocity of smoke at different openings of the building can help the fire officer determine?
The location of the fire
*faster smoke is closer to the fire seat
________ can help you understand much about the fire, how hot it is and where it is
Velocity
____Tells you how bad things are going to be
Density
Turbulent smoke velocity that has volume filled a compartment indicate that?
A flashover is imminent
Turbulent smoke velocity that is thin and dark indicates that?
A well ventilated fire is nearby
Generally speaking, turbulent smoke is always fast. Lemon or smoke can be fast or slow; a faster laminar flow indicates the presence of?
More heat
The density of smoke refers to its?
Thickness
_______ tells you how much fuel is Laden in the smoke
Thickness
Smoke _____ sets up fuel continuity
Thickness
Thick, laminar flowing smoke can ignite because of the___of the fuel to the flaming source
Continuity
Thick, black smoke in a compartment reduces the chance of life sustainability due to?
Smoke toxicology
____Tell the stage of healing and points to the location of the fire in a building
Smoke color
When flames touch surfaces that are not burning, the surfaces begin to Off gas___almost immediately
Black smoke
Blacksmoke that is high velocity and very thin, low density, is?
Flame pushed
Interpreted from the outside of the building, then, Blacksmoke means that Blank is nearby
Open and ventilated flaming
______Can also tell you the distance to a fire
Color
Fast-moving dirty white smoke indicates that the smoke you see has?
Traveled some distance, but a hot fire exists
Brown smoke from structural spaces indicates that significant heat is present. The issuance of brown smoke from gable end vents, eaves, and floor seems is a warning sign of?
Impending collapse
Brown smoke from structural spaces containing glued trusses, OSB, or LVL can indicate that____has been already lost
Critical strength
Upon seeing smoke that is the same color and velocity being pushed from multiple building seams, the ISO should inform the IC that the fire may have?
Extended to concealed spaces
In other words, the smoke VV DC has gotten as bad as it can be
Black fire
A sure sign of impending auto ignition and flashover
Black fire
Black fire can reach temperatures of over?
1000°F
The solution to black fire is the same as that for flames:
Vent and cool!
___In the air increases resistance to smoke movement but a cohesive qualities of water vapor
Humidity
In a well ventilated building, wind can speed up smoke velocity and give a false read on?
Heat or location, although it should fan flaming
Sucking, puffing, and breathing signs indicate that the fire is ?
Out of thermal balance
All spoke observations must be analyzed in proportion to?
The building
3 step process for reading smoke:
The step should be fine and or confirm your read on fire behavior in firefighting effectiveness
Step two. Analyze the contributing factors to determine whether they are affecting VVDC
3 step process for reading smoke:
This exercise should give you a strong understanding of the fire size, location, and spread potential, and it allows you to capture any warning signs of hostile fire events
Step one. View the smoke VVDC, then compare the differences in the attributes from each opening from which smoke is emitting
3 step process for reading smoke:
Remember the_________can change the meaning of VVDC
Size of the box
___Is indicative of the severity of hostile events
Density
Color can be filtered by distance or resistance, so rely on___for the true Heat story
Velocity
