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
Is the chemical breakdown of compounds into other substances by heat alone. _______ often leads to combustion
Pyrolysis
The term off-gassing is often used for pyrolysis. IT is not however accurate, so we will refer to it as slang. More accurately, surfaces that are smoking, not burning, are ___________. That is, they are releasing a mix of particulates and aerosols as well as gases.
Off-aggregating
_______ are the more prevalent solids (particulates) in smoke
Soot and ash
___Is Carbon, (officially carbon black) and Carbon can support flaming.
Soot
_____ is 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. At a structure fire, the liquids in smoke include primarily ______ and _______ (oil and tar), although there are also acids, aldehydes, and ketones to name a few.
Aerosol
moisture and hydrocarbons
Flaming plastics release hydrocarbons, as do the plastics that are decomposing due to heat. These 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
Flammable range in air__-__%
1128°F, 12-74%
Flashpoint ___°F Self ignition temperature____ and flammable range in air__-__% of hydrogen cyanide
0°F, 1000°F, 5-40%
Flashpoint __°F ,Self ignition temperature of benzene___°F, and flammable range in air to%
12°F, 928°F, 1-8%
Flashpoint __ °F , Self ignition temperature__°F of Acrolein, and flammable range in air_to__%
-15°F, 450°F, 3-31%
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 __________. The ignition of accumulated smoke also changes the basic fire spread dynamics; instead of flame spread across surfaces of contents, the fire spreads with the smoke flow.
Expansive 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
The ____-____ ____ is 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
