Your SlideShare is downloading. ×
  • Like
Chapter 07
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.


Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply


Published in Health & Medicine
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads


Total Views
On SlideShare
From Embeds
Number of Embeds



Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. Chapter 7 Reading Smoke
  • 2. Objectives
    • Define “smoke”
    • List common hostile fire events and their associated warning signs
    • List the four attributes of smoke
    • Describe what each of the four smoke attributes contributes to the understanding of fire behavior in a building
  • 3. Objectives (con’t.)
    • Define “black fire” and its relevance to firefighting efforts
    • Explain how influencing factors can affect smoke attributes
    • List the three steps in the reading smoke process
  • 4. Introduction
    • History of reading smoke
      • Older practices of reading smoke based on experience and intuitiveness
      • Low-mass synthetics and the consumer “glut” in the 1990s led to a more volatile smoke and fire environment
      • Current trends of reading smoke triggered by ISO Academies in 1990s
        • Developed by David Ross and David Dodson
  • 5. “ Smoke” Defined
    • Smoke
      • Product of incomplete combustion
      • Aggregate of solids, aerosols, and fire gases
      • Toxic, flammable, and volatile
    • Four key attributes of smoke
      • Volume
      • Velocity (pressure)
      • Density
      • Color
  • 6. Table 7-1 Properties of gases typically found in smoke.
  • 7. “ Smoke” Defined (con’t.)
    • “ Open flaming” is desirable
      • Products of combustion are minimized
      • Smoke displaces air in underventilated fires
    • Two triggers cause accumulated smoke to ignite
      • Right temperature
      • Right mixture
    • Watch smoke instead of focusing on flaming
  • 8. Hostile Fire Events
    • Events that can catch firefighters off guard and endanger them
      • Flashover
      • Backdraft
      • Smoke explosions
      • Rapid fire spread
    • ISOs must know and watch for proactive warning signs of hostile fire events
  • 9. Table 7-2 Hostile fire events.
  • 10. Volume, Velocity, Density, and Color Figure 7-2 Comparing smoke volume, velocity, density, and color can help the ISO understand fire behavior. (Photo by Keith Muratori.)
  • 11. Volume, Velocity, Density, and Color (con’t.)
    • Volume
      • May indicate the amount of fuel that is off-gassing in a given amount of space
      • High volume of smoke can occur with:
        • Hot, fast moving fire in an underventilated building
        • Dampened material
        • Low mass contents
      • High volume of smoke can create the impression of a fire
  • 12. Volume, Velocity, Density, and Color (con’t.)
    • Velocity
      • Speed at which smoke leaves a building
      • Indicator of pressure within building
      • Turbulent smoke flow
        • Ready to ignite
        • Flashover is likely to occur
      • Laminar smoke flow
        • Stable and smooth smoke flow
        • Heat of smoke is being absorbed
  • 13. Volume, Velocity, Density, and Color (con’t.)
    • Density
      • Refers to the thickness of smoke
      • Indicates how much fuel is laden in the smoke
      • Thick smoke spreads a fire event farther than less dense smoke
      • Thick black smoke in a compartment reduces the chance of life sustainability
  • 14. Volume, Velocity, Density, and Color (con’t.)
    • Color
      • Indicates the stage of heating
      • Points to the location of the fire in a building
      • The more black the smoke, the hotter the smoke
        • High velocity, low density black smoke is flame-pushed
        • Interpreted, thin black smoke indicates nearby open flaming
  • 15. Volume, Velocity, Density, and Color (con’t.)
    • Color (con’t.)
      • Can indicate distance from fire
        • Fast moving white smoke has traveled
      • Brown smoke from structural spaces
        • Indicates transition from a contents to a structural fire
    • Watch for the fastest/darkest smoke from the most resistive crack (Dave Dodson)
  • 16. Figure 7-5 Smoke that appears the same color and velocity from multiple openings indicates a deep-seated fire. (Photo by Keith Muratori.)
  • 17. Volume, Velocity, Density, and Color (con’t.)
    • Black fire
      • Slang term to describe high-volume, turbulent, ultradense, and deep-black smoke
      • Sure sign of impending autoignition and flashover
      • Can reach temperatures of over 1,000 degrees Fahrenheit
      • Solution: vent and cool!
  • 18. Other Factors That Influence Smoke
    • Weather
      • Temperature, humidity, and wind change the look of smoke
      • Cold air cools smoke faster, causes it to stall/fall, and turns it white
      • Humidity increases air resistance to smoke
      • Wind-fed fires can cause firefighters to be overrun
  • 19. Other Factors That Influence Smoke (con’t.)
    • Thermal balance
      • Notion that heated smoke rises and creates a draft of cool air into the flame source
      • Not maintained in most fires within buildings
      • Indicated by air being sucked into a building
        • Intense fire struggling for airflow
        • Sudden inflow of air can trap firefighters
  • 20. Other Factors That Influence Smoke (con’t.)
    • Container size
      • All smoke observations must be analyzed in proportion to the building
      • Size of the building is an important indicator of the significance of the smoke leaving it
        • Example: light, thin smoke showing from more than one opening of a very large building may indicate a large, dangerous fire
  • 21. Other Factors That Influence Smoke (con’t.)
    • Firefighting efforts
      • Four attributes of smoke should change in a positive manner if fire stream and ventilation efforts are appropriate
        • Volume should rise
        • Velocity should gradually slow and change to laminar flow
        • Density should thin
        • Color should eventually turn white
  • 22. Other Factors That Influence Smoke (con’t.)
    • Firefighting efforts (con’t.)
      • Forced-ventilation tactics should cause an increase in smoke velocity
      • PPV tactics are contraindicated if:
        • Smoke is turbulent
        • Location of fire seat is unknown
        • Fire is in a vented, combustible void space
        • Smoke become thicker and darker during PPV use
  • 23. Reading Smoke: The Three-Step Process
    • Step 1
      • View the volume, velocity, density, and color of smoke
      • Compare the difference in the attributes from each opening from which smoke is emitting
  • 24. Reading Smoke: The Three-Step Process (con’t.)
    • Step 2
      • Analyze contributing factors (size, weather, firefighting efforts) to determine if they are affecting volume, velocity, density, and color
    • Step 3
      • Determine the rate of change of each attribute
        • If deterioration can be measured in seconds, firefighters are at risk
  • 25. Table 7-3 Reading smoke shortcuts.
  • 26. Summary
    • Predicting fire behavior is based on understanding:
      • Physical and chemical properties of smoke
        • Volume, velocity, density, and color
      • Proactive warning signs of hostile fire events
      • Factors that influence smoke
        • Weather, container size, thermal balance, and firefighting efforts
      • Rate of change in smoke attributes