Sarnia Fire Rescue Services
Smoke Conditions for Structural Firefighting
Smoke
Attributes
Go
Fast Attack Mode
Command Mode
Changing Conditions
Marginal
Do Not Go
Command Mode
Smoke Visible From Outside Structure
Small volume of smoke may
Large volume of smoke may
Pressurized smoke (volume and
indicate small fire “or”
indicate fire room/area is full. heat) – Pushing, dense black
Hot complete burning may
Lack of ventilation.
smoke indicate hot fast-moving
VENTILATE
fire…VENTILATE
emit little visible smoke
NOTE: Rapid change in smoke volumes may indicate fire
1. Rapid Increase – heavy fuel load has just been added to a hot
events.
fire.
2. Smoke Diminishes – flashover just took place.
Smoke Velocity (Pressure)
Smoke velocity that rises and Smoke velocity caused by
Smoke leaving an opening is
gradually slows – caused by
restricted volume immediately
turbulent (BEWARE Hostile Fire
Fire Officer needs to know
slows and balances with
Event - flashover, backdraft likely
WHAT has caused the smoke to heat, consider size of area.
outside airflow.
to occur)…VENTILATE
pressurize? Heat or Volume.
CAUTION: Pressurized smoke leaving a small crack can be a more significant observation than the velocity of smoke leaving a
large opening.
Smoke Volume
(The amount of fuels off-gassing
within a given area)
Smoke Density (How “thick”
the smoke is indicates the
quality of burning)
Light or Thin Smoke Density indicates complete burning,
ventilation (incipient burning).
Moderate Smoke Density –
indicates fire in growth stage
with a thermal balance
Thick Black Smoke with signs
of HEAT (velocity) indicates a
greater potential for flashover or
rapid fire spread… VENTILATE
CAUTION: Smoke that becomes rapidly dense indicates an imminent flashover. Density that rapidly changes from dense to light
indicates Flashover just took place. Should see a change in velocity or that fire has adequately vented.
NOTE: Smoke must be considered as un-burned fuel.
Smoke Colour
White Smoke (first heated
Brown Smoke – unfinished
BLACK FIRE – high volume,
turbulent velocity, dense black
1. Tells us the stage of heating
fuels, dampened fuels)
wood (floor joists, wall studs,
Dark Grey (full involvement,
smoke…VENTILATE
and helps us find the location of
light weight structural
BACK DRAFT - potential
fire.
plastics and painted surfaces).
components)
Yellowish & lazy, dense smoke
2. Black smoke turns grey further Black (materials further heated, Warning sign for potential
collapse.
…VENTILATE
from seat of fire.
open flaming)
Structure fires rarely have single fuel source emitting smoke i.e. various contents, building materials.
Resources
Ontario Fire College, Company Officer Program Doug Outtrim CO-401, 501, 502
John Kingyens, Training Officer- Sarnia Fire Rescue
Dave Dodson, Response Solutions, The Art of Reading Smoke
Delmar Firefighter Handbook, Fire Behavior, Delmar Incident Safety Officer
Sarnia Fire Rescue Services
Smoke Conditions for Structural Firefighting
Smoke constant in colour and velocity from various openings may indicate fire is deep seated with-in building.
Resources
Ontario Fire College, Company Officer Program Doug Outtrim CO-401, 501, 502
John Kingyens, Training Officer- Sarnia Fire Rescue
Dave Dodson, Response Solutions, The Art of Reading Smoke
Delmar Firefighter Handbook, Fire Behavior, Delmar Incident Safety Officer