Introduction to Fire
The Fire Triangle
Heat Matches
Sun
Cigarette Butts
Ignition Sources
Fuel Wood
Oil
Paper
Gases
Air, Oxygen, or Oxidizers
All three elements must be present to initiate a fire.
The Fire Tetrahedron
Heat Matches
Sun
Cigarette Butts
Ignition Sources
Fuel Wood
Oil
Paper
Gases
Air, Oxygen, or Oxidizers
Once a fire has started it can only be suppressed when one of the three elements is removed, thus stopping the chemical chain reaction.
Chemical Chain
Reaction
The Fire Tetrahedron
Heat Matches
Sun
Cigarette Butts
Ignition Sources
Fuel Wood
Oil
Paper
Gases
Air, Oxygen, or Oxidizers
Water:
Eliminates Heat
CO2: Dry Chemical:
Eliminates Oxygen
Gas Shutoffs:
Eliminates Fuel
Chemical Chain
Reaction
Fire Myths and Fire Truths: Visibility
Myth
Visibility is clear.
Truth
Fires are dark.
Kurt Russell in BackdraftOther great Kurt Russell movies include Silkwood,
Tango & Cash, Tequila Sunrise, and Miracle.
Note that the firefighter in the doorway cannot be seen.
Fire Myths and Fire Truths: Time
Myth
There is ample time.
Truth
There is little or no time.
Fire Myths and Fire Truths: Death
Myth
People burn to death.
Truth
People die from smoke inhalation. Carbon Monoxide.
This is why smoke detectors are of greater
value than heat detectors in most instances.
Classifications of Fire
Class A
Ordinary Combustibles• Paper• Wood• Plastics
Class A fires will generally leave an ash.
Class B
Flammable Liquids and Flammable Gases• Gasoline• Oil• Acetone
Class C
Class A or B Fires with an Electrical Hazard• Energized Electrical Equipment• Outlets
Class D
Combustible Metals• Potassium• Magnesium• Sodium
Class K (Kitchen)
Cooking Oil and Fat
Types of Fire Extinguishers
Class A
Water• Eliminates Heat
Class AB
Foam• Eliminates Oxygen
Class BC
CO2, Dry Chemical, or Halon• Eliminates Oxygen
Class ABC
Dry Chemical• Eliminates Oxygen
Class D
Dry Powder• Eliminates Oxygen
Class K (Kitchen)
Wet Chemical• Eliminates Oxygen
Note: Many Class K extinguishers are also suitable for Class A fires.
Class AC
Water Mist• Eliminates Heat & Protects Equipment
Using an Extinguisher
When To Use?
• When it is absolutely necessary.
• When the is a fire between you and your escape route.
• When the fire is relatively contained; e.g., a garbage can.
• When there is a realistic opportunity to put out the fire.
YES NO
Positioning
• Between the fire and an exit or escape route.
• Back three to four feet from the front of the fire.
• Always back away from the fire, keeping an eye out for flare-ups.
P.A.S.S.
• Pull the Pin
• Aim (base & front of fire)
• Squeeze (the handle)
• Sweep (moving front to back)
Fire Alarm Systems
Alarm Activation
1. Pull Station
2. Heat Detector
3. Smoke Detector
4. Sprinkler
5. Electrician
6. Malfunction
Fire Suppression Systems
Hoses & Standpipes
• Hoses are a LAST resort.• Standpipes are for fire
department use only. Do not uncap them.
Sprinklers
• Individual sprinklers will activate when heated to the appropriate temperature.
• Release about 75 to 150 liters/minute.
INERGEN®; Halon; CO2 Systems
• Deprive fires of oxygen.
• Dangerous for humans in such areas.
• LSC, Chemical Stores Facility, Tupper.
Fire Evacuation Procedures
Upon Hearing an Alarm
• Exit the room.• Close the door behind you (leave unlocked).• Follow the wardens instructions.• Follow set evacuation routes.• Exit the building.• Keep back from the building (min 50m).• Wait for instructions from wardens, Dal
Security, or the HRM Fire Service.
If YOU Discover Fire
• Try and put out if it meets previous criteria.
• Close the door to the room and activate a pull station.
• Exit the building.
• Give all information to wardens, Dal Security, or HRM Fire Service.
Persons with Disabilities
• If you have a disability that prevents you from leaving a building via stairwells, set up a buddy-system.
• Stay in designated “shelter-in-place” areas.
Re-Entering a Building
• DO NOT re-enter a building until given the “OK” by the wardens, Dal Security, or the HRM Fire Service.
The Law
• You MUST leave a building upon hearing an alarm, even in the case of a fire alarm drill.
• The Fire Service has the authority to fine people who do not evacuate buildings.
Final Thoughts
Fires are Dangerous
• Treat fire and fire safety with respect.
• There are rarely second chances.
• Open flames are not permitted at Dalhousie unless cleared through the Safety Office.
Fires are Rare on Campus
• Dalhousie has had fires in the past, but over the past decade they have been small, with minimal damage and no serious injuries or deaths.
• Small houses and buildings, prevalent at Dalhousie, present the highest risk of fire.