Reading Smoke Essentials

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Questions and Answers

Where is reading smoke adapted from?

The art of reading smoke by Dave Dodson and Reading smoke by Gary Ells.

Why do we read smoke? (5 things)

To help determine what we have, where it's at, predict where it's going, predict what is going to happen, and better plan to deal with it.

What will evaluating smoke allow us to determine and plan for? (5 things)

Size and extent of the incident, speed and direction of fire spread, degree of heat release and stage of fire, possible adverse fire events, and appropriate prioritization of strategics and tactics.

What is smoke?

The visible vapor and gases given off by a burning or smoldering substance, especially the gray, brown, blackish mix of gases and suspended particles resulting from combustion. Signup and view all the answers

The specific definition of smoke matters less than .

What is in it. Signup and view all the answers

What are toxic gases included in smoke?

Carbon monoxide, hydrogen cyanide, nitrogen oxides, hydrogen sulfide, hydrogen chloride. Signup and view all the answers

Besides being toxic and poisonous, most toxic gases are ______.

flammable. Signup and view all the answers

Carbon monoxide has a flammable range of what at 1200F?

12-75%. Signup and view all the answers

What is the composition of smoke?

Gases, aerosols, particulates. Signup and view all the answers

The bottom line is, smoke is ___ _.

unburned fuel. Signup and view all the answers

Why is reading smoke more important now than ever before?

Fuels have changed. Signup and view all the answers

Today's structures exhibit materials with considerably less mass than yesterday's. Why?

The increased use of engineered materials such as trusses. Signup and view all the answers

In terms of a structure fire, mass = what?

Time. Signup and view all the answers

How has the composition of fuels changed?

There are more synthetic materials such as plastics. Signup and view all the answers

Plastics put off ____ the BTU's as normal class A fuels.

Twice. Signup and view all the answers

Plastics produce _ clouds of smoke with more flammable gases than normal class A fuels.

Thick black. Signup and view all the answers

Why is understanding the composition change of fuel important?

There is more heat in the structure and more flammable smoke. Signup and view all the answers

Structures have changed as well. How?

There is more emphasis on energy efficiency so they are better insulated and hold in more heat. Signup and view all the answers

Better insulation leads to?

Faster development of hostile events. Signup and view all the answers

In what ways have fuels changed?

Mass, Composition, Structures have all changed. Signup and view all the answers

How has our equipment changed?

Better turnouts, use of SCBA, faster notification times. Signup and view all the answers

Equipment changes allow us to?

Go farther into and stay longer in hotter environments and arrive on scene prior to flashover. Signup and view all the answers

All changes in fuel and equipment add up to an increased exposure to extreme _ events for today's FF.

Fire behavior. Signup and view all the answers

The ability to read smoke will allow us to?

Avoid hostile events and deal with them safely. Signup and view all the answers

Smoke has trigger points. What are they?

Flash point, fire point, ignition temperature. Signup and view all the answers

_ _ of the smoke is a very important factor to consider.

Flammable range. Signup and view all the answers

When predicting fire events, we need to be able to determine what three things?

What stage the fire is in, is the box absorbing heat, is it laminar or turbulent smoke flow. Signup and view all the answers

Smoke flow can be either _ or __.

Laminar, turbulent. Signup and view all the answers

What fire events do we want to predict?

Flashover, backdraft, smoke explosion, rapid fire spread. Signup and view all the answers

What is flashover?

The transition between the growth and fully developed stage. Signup and view all the answers

What are interior warning signs of flashover?

Heavy interior smoke conditions, rollover occurring, high heat banking down suddenly. Signup and view all the answers

What are exterior warning signs of flashover?

Heavy, dark turbulent smoke exiting, auto ignition in the exiting smoke, advanced stages of burning. Signup and view all the answers

What is backdraft?

An explosion caused by the sudden introduction of oxygen to a smoldering, oxygen-deprived fire. Signup and view all the answers

What are warning signs of backdraft?

Yellowish-grey smoke, whistling, bowing windows, sealed container, pressurized smoke from small cracks, little or no visible flame from exterior, smoke-stained windows. Signup and view all the answers

What is smoke explosion?

An explosion in adjoining compartments where the smoke is below ignition temperature. Signup and view all the answers

What are warning signs of smoke explosion?

Large amounts of cool smoke in rooms adjacent to fire room, growing fire, increasing smoke density, air intake overtaking smoke exiting. Signup and view all the answers

Rapid fire spread is usually ______ influenced.

Container. Signup and view all the answers

What should you look for in regards to rapid fire spread?

Fast moving smoke in high pressure zones. Signup and view all the answers

Fuel for fire spread is _ vs. contents surface flaming.

Smoke driven. Signup and view all the answers

Cold lazy smoke could cause ____ _ while fast moving smoke could cause _ _ ___

Smoke explosion, rapid fire spread. Signup and view all the answers

Reading smoke to predict what is happening or going to happen is a ____ step process.

Four. Signup and view all the answers

Visible fire is easy to read, look beyond it for the .

real story. Signup and view all the answers

When reading smoke, the observations are typically made from the ________.

outside. Signup and view all the answers

_______ observations hide the real picture.

Inside. Signup and view all the answers

What are the 4 steps to reading smoke?

<ol> <li>Evaluate the smoke, 2. Weigh all factors, 3. Judge the rate of change, 4. Predict the event.</li> </ol> Signup and view all the answers

What 4 attributes should we assess when evaluating the smoke?

Volume, velocity, density, color. Signup and view all the answers

What does volume of smoke mean?

The amount of smoke visible. Signup and view all the answers

What does the volume of smoke tell us?

How much fuel has off gassed. Signup and view all the answers

Volume of smoke is relative to?

The box. Signup and view all the answers

Volume of smoke is typically described as or .

light, heavy. Signup and view all the answers

What is the velocity of smoke?

The speed of the smoke exiting. Signup and view all the answers

Velocity of smoke leaving the building is indicative of what?

The amount of pressure within the building. Signup and view all the answers

The velocity of smoke indicates either _ or __.

volume, heat. Signup and view all the answers

The velocity of smoke helps us locate?

The actual fire. Signup and view all the answers

What is the rule of thumb in regards to velocity?

The hotter the fire, the more turbulent the smoke. Signup and view all the answers

What is the most important factor when reading smoke?

Density. Signup and view all the answers

What is the density of smoke?

How thick the smoke is. Signup and view all the answers

Changes in density can indicate?

Sudden change in conditions or spread of fire. Signup and view all the answers

Density tells us the ______ of burning.

Quality. Signup and view all the answers

Density helps us predict the likelihood of?

An adverse event. Signup and view all the answers

Density tells us how bad things are going to be.

True Signup and view all the answers

What are the colors of smoke?

Off white through dense black. Signup and view all the answers

Odd colors of smoke may indicate?

Hazmats. Signup and view all the answers

Looking at the color of smoke will tell us the _ .

Stage of heating. Signup and view all the answers

The color of smoke will help us determine the _______ of fire.

Location. Signup and view all the answers

Read the factors, what is it? Volume: Light, Velocity: Lazy and slow, Density: Thin and transparent, Color: Off white to gray.

Incipient fire. Signup and view all the answers

Read the factors, what is it? Volume: Heavy, Velocity: Moderate and very turbulent, Density: Very opaque, Color: Dark grey to black.

Pre-flashover. Signup and view all the answers

Read the factors, what is it? Volume: Heavy, Velocity: Rapid and turbulent, Density: Translucent to opaque, Color: Grey to dark grey.

Freeburning. Signup and view all the answers

Read the factors, what is it? Volume: Heavy, Velocity: Moderate speed and heavy turbulence, Density: Opaque to very opaque, Color: Dark gray, brown, yellowish.

Air controlled fire. Signup and view all the answers

Read the factors, what is it? Volume: Large amounts of light smoke, no smoke, puffing out of cracks, Velocity: Puffing, Density: Translucent to opaque, Color: Light gray to gray, yellowish gray.

Backdraft. Signup and view all the answers

Weighing all factors includes?

Container, thermal balance, weather, firefighting efforts/effect. Signup and view all the answers

How do you judge the rate of change? (step 3)

Look at how fast are the smoke conditions getting better or worse. Signup and view all the answers

One hostile event can _____ to another.

Lead. Signup and view all the answers

_____ your observations.

Communicate. Signup and view all the answers

Warning signs are not always visual, therefore you should?

Trust your instincts. Signup and view all the answers

Sealed buildings ______ the smoke.

Filter. Signup and view all the answers

Prior to entering, you should allow the smoke to _____ for a few seconds. Why?

Exit. Signup and view all the answers

What is 'burping the building'?

Allowing smoke to exit for a few seconds before you enter. Signup and view all the answers

The higher the hydrocarbon content of the fuel:

More BTUs released, higher temperatures, greater expansion and pressure created. Signup and view all the answers

Hot smoke moves _____ near the seat of the fire.

Faster. Signup and view all the answers

How can you observe how fast smoke is moving while inside a structure?

Hold your handlight vertical. Signup and view all the answers

Gray-black smoke with velocity and turbulence suddenly clearing indicates?

Flashover in seconds. Signup and view all the answers

What does dense black smoke indicate?

Flammable liquids, plastics, hydrocarbon-saturated materials. Signup and view all the answers

What does dirty white-gray smoke with no pressure that hangs in the air indicate?

Mattress fire or food on the stove. Signup and view all the answers

What does a large volume of white smoke and no heat, or smoke that is translucent indicate?

Void space fire. Signup and view all the answers

Operating sprinklers show grey smoke outside with cool, dense smoke inside. What is this prime for?

Smoke explosion. Signup and view all the answers

Fires in unventilated void spaces will _ or have a .

backdraft, smoke explosion. Signup and view all the answers

What are common void spaces you should address early?

Knee walls, bowstring truss attics. Signup and view all the answers

The bigger the void space:

The more dangerous. Signup and view all the answers

When dealing with void spaces, ventilate them vertically or prior to opening.

Apply water. Signup and view all the answers

How would you apply water to a void space?

Piercing nozzle or small access holes. Signup and view all the answers

Heat creates _____, this pushes the smoke out.

Pressure. Signup and view all the answers

Study Notes

Reading Smoke Overview

Reading smoke is a crucial skill in firefighting adapted from works by Dave Dodson and Gary Ells.

Purpose of Reading Smoke

Aids in determining fire presence, location, and predictive analysis of fire behavior.
Assists in strategic planning for firefighting efforts.

Evaluating Smoke

Key factors include:
- Size and extent of the incident
- Speed and direction of fire spread
- Degree of heat release and fire stage
- Possible adverse fire events
- Prioritization of tactics.

Definition and Composition of Smoke

Smoke is the visible vapor from burning substances, primarily composed of gases, aerosols, and particulates.
Contains toxic gases like carbon monoxide, hydrogen cyanide, and nitrogen oxides.

Flammability and Toxicity

Most toxic gases in smoke are also flammable.
Carbon monoxide has a flammable range of 12-75% at 1200°F.

Composition Changes in Fuels

Recent years have seen an increase in synthetic materials, which burn hotter and yield thicker black smoke.
Plastics generate double the BTUs compared to traditional Class A fuels.

Structural Changes

Modern buildings use engineered materials, leading to lower mass and better insulation, increasing heat retention.
Better insulation can result in faster hostile event development.

Firefighting Equipment Advances

Improvements include better turnout gear, SCBA usage, and faster notification systems.
Such advancements allow for deeper entry and extended time in hotter environments.

Smoke Behavior Prediction

Understanding changes in smoke with regards to volume, velocity, density, and color can inform about the fire's nature.
Three predictive assessments involve fire stage, heat absorption, and smoke flow characteristics.

Flashover and Backdraft Signs

Flashover is marked by heavy smoke, rollover, and faint visible flames.
Backdraft is indicated by yellowish-gray smoke, sealed containers, and pressurization signs.

Smoke Explosion Risks

Smoke explosions occur in adjacent chambers with smoke below ignition temperature, indicated by increasing smoke density and cool smoke in neighboring rooms.

Reading Smoke Techniques

Observations should be made from the outside while considering potential danger signs inside.
Four steps in smoke reading involve evaluating, weighing factors, judging changes, and predicting fire behavior.

Attributes to Assess When Reading Smoke

Analyze smoke volume, velocity, density, and color for diagnostics:
- Volume: amount of smoke
- Velocity: indicates internal pressure
- Density: reflects conditions and potential fire spread
- Color: informs about fuel type and fire stage.

Key Indicators of Fire Stages

Incipient fire shows light smoke volume and slow velocity.
Pre-flashover displays heavy, turbulent smoke.
Freeburning smoke is heavy with rapid flow, hinting at a well-ventilated fire.

Void Spaces and Fire Behavior

Void spaces (e.g., knee walls) pose significant risks and should be ventilated appropriately.
Use piercing nozzles or create small access holes to apply water safely in these areas.

Final Considerations

Trust instincts as warning signs may not always be visually apparent.
Address void spaces early in firefighting strategy to mitigate risks.

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Description

This quiz covers the fundamental concepts of reading smoke, adapted from the works of Dave Dodson and Gary Ells. Explore its purposes, including determining fire dynamics and planning responses. Test your understanding of this essential skill in firefighting.