Art of Reading Smoke

Question 1

What has led to a more volatile fire environment?

Answer 1

Low mass synthetics and big box trends

Question 2

What are the four attributes of smoke leaving a structure?

Answer 2

volume, velocity, density, and color

Question 3

A comparative analysis of the 4 attributes can help an officer

Answer 3

determine the size and location of the fire and hostile fire conditions such as flashover

Question 4

Smoke leaving a structure needs to be interpreted as an aggregate of

Answer 4

solids, aerosols, and fire gases that were toxic, flammable, and volatile

Question 5

The solids suspended in smoke are

Answer 5

carbon (soot), dust, and airborne fibers

Question 6

The aerosols in smoke are

Answer 6

hydrocarbons (oils/tar)

Question 7

Fire gases in smoke contain

Answer 7

carbon monoxide, hydrogen cyanide, acrolein, hydrogen sulfide, and benzene

Question 8

What ultimately dictates fire behavior?

Answer 8

Hot flammable smoke

Question 9

What are the products of fire limited to during open flame

Answer 9

Carbon, carbon dioxide, and water vapor

Question 10

Where does smoke flammability begin?

Answer 10

FIre inside a compartment when heat is absorbed into the materials such as contents and walls/ceilings

Question 11

What two triggers cause smoke to ignite

Answer 11

right temp and right mixture

Question 12

What is an underventilated fire

Answer 12

when off-gassed smoke displaces air leading to increased levels of CO

Question 13

What changes basic fire spread dynamics

Answer 13

accumulated smoke. Flame follows smoke flow

Question 14

Which attribute by itself tells you very little about a fire

Answer 14

Volume

Question 15

What emits very little smoke

Answer 15

a hot clean burning fire

Question 16

A hot fast-moving fire in an under ventilated building will create

Answer 16

a tremendous volume of smoke

Question 17

What kind of smoke will dampened materials create?

Answer 17

it’ll burn slowly and create lots of smoke that’s light in color

Question 18

What changes in today’s contents create large volumes of smoke with little flame?

Answer 18

low-mass

Question 19

What does the volume of smoke in a structure tell you

Answer 19

size of the fire based on the size of the occupancy (small fire can fill a small restaurant with smoke but a large fire would be needed to fill a warehouse)

Question 20

What is velocity

Answer 20

the speed at which smoke leaves the structure

Question 21

What does smoke velocity indicate?

Answer 21

The pressure that has built up in the structure

Question 22

From a fire behavior standpoint, what two things cause velocity

Answer 22

heat and volume

Question 23

Velocity caused by heat will

Answer 23

rise and slow gradually after it leaves the structure

Question 24

Velocity caused by volume will

Answer 24

immediately slow and balance with outside airflow

Question 25

Turbulent smoke leaving a structure indicates

Answer 25

flashover is likely to occur

Question 26

How is turbulent flow created?

Answer 26

rapid molecular expansion of the gasses within the smoke restricted by the container

The expansion is caused by radiant heat feedback from the container that can’t absorb any more heat

Question 27

A box that is still absorbing heat from smoke will create smoke that’s

Answer 27

more laminar

Question 28

What is the most important smoke observation?

Answer 28

Turbulent vs laminar

Question 29

Comparing smoke velocity at different openings can help

Answer 29

locate the seat of the fire - faster moving smoke will be closer to the fire

Question 30

What is the smoke velocity outside the fire determined by

Answer 30

the exhaust opening

Question 31

What happens to smoke as the distance from the fire increases

Answer 31

smoke follows the path of least resistance and will lose velocity

Question 32

what must happen when attempting to locate the fire when comparing openings

Answer 32

you must only compare like size openings

Question 33

What does smoke density tell you?

Answer 33

how bad things are going to be - Density refers to the smoke “thickness” which tells you how much laden fuel is in the smoke

Question 34

What will thicker smoke indicate?

Answer 34

how far fire will spread during flashover. Thicker smoke will spread fire farther than thinner smoke

Question 35

What does Thick black smoke do?

Answer 35

reduces the chance of survivability for victims

Question 36

Thick laminar smoke can be a sign of

Answer 36

flashover

Question 37

What does smoke color tell first-arriving companies

Answer 37

stage of heating and location of fire

Question 38

What color smoke will all solid materials emit when first heated?

Answer 38

white smoke which is mostly moisture

Question 39

What happens to the smoke of solids as they break down when heated

Answer 39

wood turns tan/brown and plastics turn grey

as materials are heated the smoke will turn all black

Question 40

What happens when flame touches a surface

Answer 40

the smoke will turn black almost immediately

Question 41

Black smoke that is high velocity and very thin indicates

Answer 41

flame pushed smoke and that the fire is nearby

Question 42

What does brown smoke indicate

Answer 42

that wood is reaching ignition temperature which signals the fire is transitioning from a contents fire to a structure fire

Question 43

White and grey smoke can indicate what depending on the velocity

Answer 43

that the smoke has traveled some distance away from the fire

Question 44

White smoke that has its own pressure indicates______ while lazy white smoke indicates ______

Answer 44

Distance traveled from the fire

early stage heating

Question 45

Brown smoke from structural spaces containing OSB or LVL indicates

Answer 45

critical strength has been lost and collapse is impending

Question 46

Smoke that is uniform from multiple openings indicates

Answer 46

the fire is in a concealed space or deep seated

Question 47

Black fire is indicative of

Answer 47

impending autoignition or flashover

black fire smoke can reach temps of 1000 degrees

Treat black fire like actual flames. Heat and cool

Question 48

What changes the appearance of smoke

Answer 48

Wind, thermal balance, ventilation openings, water streams, and sprinkler systems