A” fires - University of Melbourne

Report
Fire Extinguishers: types and uses
John Carmichael OH&S and IM
Learning outcomes
1.
2.
3.
4.
5.
6.
Describe the elements of fire
Identify the classes of fire
Identify extinguishing agents
Identify types of fire extinguishers
Identify when it is safe to fight a fire
Demonstrate use of fire extinguishers
Fire
Chemical reaction in which heat, smoke,
and light, is produced-called combustion.
Combustion is sustained by the
production of free radicals.
Basic fire behaviour
• Heat and smoke rises
• Smoke will enter through small
holes or gaps in most materials
• Fire will spread out and upwards
Stop the spread of fire and smoke
Close Windows
Close Doors
Limits oxygen supply
Confines the fire and
smoke to a smaller
area
The four sides of this tetrahedron
represent fire :• Heat
• Oxygen
• Fuel
• Chemical Reaction
Controlling a fire
• HEAT – Cool
• OXYGEN – Smother
• FUEL – Starvation
• CHEMICAL REACTION - Inhibit
Cooling
Water to cool the fire
Water absorbs the heat
Burning fuel
Heated vapour
Water is fairly cheap
Very common method of
extinguishment
Smothering
Reduce the oxygen supply to the fire
• Sand or earth
• Fire blankets
• Powder and foam
fire extinguishers
Starvation
Remove the fuel from fire
Can be very difficult!
Examples:
Shut off gas
Construct fire breaks
Use non combustible
materials
Inhibiting the chemical reaction
Apply a chemical reagent that inhibits flame reaction
Classes of fires
A” Class Fires
“B” Class Fires
“C” Class Fires
“D” Class Fires
“E” Class Fires
“F” Class Fires
Class “A” fires
Ordinary Combustible Solids
Wood, paper, cloth, plastics, rubber, coal,
carbon based compounds etc.
Class “B” fires
Flammable & Combustible Liquids
Petrol, oil, paint, thinners, kerosene,
alcohol, etc.
Class “C” fires
Flammable Gases
L.P.G., Butane, Acetylene, Hydrogen,
natural gas and Methane etc.
Class “D” fires
Combustible Metals
Magnesium, aluminium, sodium,
lithium, calcium, potassium etc.
Class “E” fires
Electrical Fires
Computers, switchboards, power-boards,
etc.
Class “F” fires
Cooking Oils and Fats
Chip cookers, deep fryers, etc.
Extinguishing Agents
• Dry Chemical / Powder
• Carbon Dioxide (CO2)
• Water
• Foam
Water
Red colour
Cooling
Discharge time ~ 60 - 90 secs
Range up to 6.0 m
Note: Conducts Electricity
Foam
Blue colour band
90% water, 10% A.F.F.F.
Cooling and smothering
Discharge time ~ 60 seconds
Range up to 4.5 m
Note: Conducts Electricity
Wet chemical
Oatmeal colour band
Cooling and smothering
Discharge time ~ 60 seconds
Range up to 4.5 m
Ideal for industrial kitchens
Note: Conducts Electricity
Dry powder
White colour band
Inhibits flame reaction
Smothering
Discharge time ~ 10 - 15 secs
Range up to 3.0 m
Carbon dioxide (Co2)
Black colour band
Smothering
Discharge time ~ 10 – 15 secs
Range up to 2.0 m
B.C.F. Fire Extinguishers
Yellow in colour
Toxic to humans
Can cause death or
unconsciousness
Contact Maintenance to dispose
Banned since 31 December
1995
Fire extinguishers
Handle
Service tag
Nozzle
Instructions
Guage
Pin
Fire hose reels
Hose nozzleadjustable
spray
Water on/off
Water stream
on/off
Fire blanket
Fire resistant fabric
Smother flames
Keep in kitchen
One use only
Signage
Extinguisher location
Discovering a fire
Upon discovering a fire:
1. Assess the situation
2. Assist persons in the immediate area
3. Restrict the danger area/s
4. Raise the alarm
5. Attack the fire (Only if safe to do so)
6. Evacuate to safety
When is it safe to attempt to fight a fire?
• Not explosive in nature
• Correct equipment
• Properly trained
• Size of fire
• Safe escape
• Alarm raised
In conclusion
• Fire extinguishers can help
prevent small fires getting larger
• Fire fighting is for the Firefighters
• Don’t forget to look for fire fighting
equipment in your work area!
More information
• Emergency management
– http://safety.unimelb.edu.au/support/emergency/
• Security
– http://www.pcs.unimelb.edu.au/services_a
nd_requests/security_and_access/index.ht
ml
© Copyright The University of Melbourne 2011

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