drr fire Flashcards
(18 cards)
include all types of live flames, causes of sparks,
hot objects, and chemicals that are potential for ignition, or
that can aggravate a fire to become large and uncontrolled.
- also include all types of potential threats to fire prevention
practices, firefighting, built-in fire safety systems and
situations that restrict the escape of people from an affected
building or area in the event of a fire.
Fire Hazard
Fire needs three elements to burn:
(1) Oxygen, (2) Heat, and (3)
Fuel
heat transfer through empty space by
electromagnetic waves
Radiation
– heat transfer through a medium without visible
motion (mere contact)
Conduction
heat transfer through a circulating medium
(usually fluids)
Convection
skin is red
- “Cool a burn” = Hold burn under running cool
tap water
First Degree
skin is red and blistery
- “Cool a burn” and see a doctor if the burn is
large or blisters are damaged.
Second Degree
skin is gray, dry, and with no feeling
- Don’t remove clothing from burn area.
- Go to emergency room immediately
Third Degree
fuels are ordinary combustibles such as wood, paper,
plastic, or anything that leaves ash.
Class A
fuels are flammable or combustible liquids like
petroleum oil, gasoline, paint, and flammable gases
such as propane and butane.
Class B
fuels are energized electrical fires like motors,
transformers, and appliances. Once the power or
source of electricity is removed, the fire becomes one
of the other classes of fire.
Class C
– fuels are combustible metals like potassium, sodium,
aluminum, titanium, and magnesium.
Class D
fuels are cooking oils, grease such as animal fat and
vegetable fats.
Class K
heat, oxygen, and fuel source combine
and have a chemical reaction (fire triangle is
complete)
- Also known as incipient
- 2 types: Piloted ignition and auto ignition
Piloted ignition – fuel + oxygen + external heat
source (spark)
Auto ignition – combustion by heat without
spark or flame
- Smoke and heat is produced
- Oxygen supply = 21%
- Does not have high temperatures
- Breathing is barely affected
Ignition – First stage:
Expansion of fire, depletion of oxygen supply, and
increase in temperature
- Also known as free burning phase
- Oxygen supply is less than 21%
- Temperatures reach between 640° to 870°
- Factors that affect the growth of fire:
(1) fuel load
(2) fuel type
(3) orientation of fuel relative to fire
(4) available oxygen
(5) ceiling height
(6) potential for thermal layering
- Fire influences the environment and is influenced by
the environment
- High levels of carbon monoxide
- Breathing becomes difficult
- Highly dangerous flashovers may occur anytime
Growth
All fuels have been ignited and burning.
- Hottest phase of a fire
- Fire is now dependent on the amount of oxygen.
- Spread of flammable gases within the area
- Oxygen supply < 16%
- Too much carbon monoxide is present
III. Fully Developed
Fire starts to diminish as fuel and/or oxygen is
consumed
- Also known as smoldering phase
- Usually the longest stage of a fire
- Characterized by significant decrease in oxygen and
fuel
- Backdraft could potentially occur.
Decay
phenomenon in which fire that has consumed all
available oxygen suddenly explodes when more
oxygen is made available, usually because a door
or window is opened
Backdraft
