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NEBOSH Fire Certificate
Element 4 Part 2
Issue Oct 2011
Fire Protection in Buildings
FIRE EXTINGUISHER LOCATION,IDENTIFICATION AND USE
FIRE EXTINGUISHERS ARE PROVIDED TO REMOVE PARTS OF THE TRIANGLE OF FIRE THEREBY PREVENTING COMBUSTION FROM CONTINUING.
HEAT
OXYGENFU
ELSMOTHERING
STAR
VATI
ON
COOLINGFire Extinguisher
CLASSIFICATION OF FIRES
• There is not a universal fire-extinguishing agent and therefore there is a possibility that using particular types of fire extinguishers on ignited materials or liquids may make the fire considerably worse and place the fire fighter at risk.
• Under British Standard EN-2 (Classification of Fires), fires have been divided into broad classifications for extinguishing purposes. This will assist in selecting the most effective fire-extinguishing agent to be used, on the most appropriate type of fire and burning material
SIGN, COLOUR & PICTOGRAM
CLASSIFICATION OF FIRES
Wood / Furnishings Etc CLASS A: All solid materials, usually organic origin nature (contains compounds of carbon) and generally produce glowing embers - i.e. wood, textiles, curtains furniture and plastics
Flammable Liquids & Solids
Class B:All flammable liquids and solids, which can also be sub-divided into: Non-miscible with water (i.e. petrol, oils, solvents, paints & waxes) Polar Liquid Fires (Hydrophilic/Miscible) with water (e.g. alcohol, methanol, acetone, propanol, & ethanol etc) - sometimes known as Polar Liquids.Note: Hydrophilic = having an affinity with water / Miscible = 'capable of being mixed'
Fires involving Gases CLASS C: Class ‘C’ fires involve Natural Mains Gas, Liquid Petroleum Gases (e.g. LPG - Butane & Propane etc) and Medical or Industrial gases.
SIGN, COLOUR & PICTOGRAM CLASSIFICATION OF FIRES
Fires Involving Metals CLASS D:Class ‘D’ fires involving metals or powdered metals etc (where water is generally ineffective and / or dangerous). Specialist Dry Powders are produced for certain Class ‘D’ fires (i.e. M28), particularly those involving alkali metals such as Sodium & Potassium. These Dry Powders extinguish metal fires by fusing the powder to form a crust, which excludes oxygen from the surface of the molten metal. A specific agent is added to prevent the powder from sinking into the surface of the molten metals
Electrical Electrical fires are not considered to constitute a fire class on their own, as electricity is a source of ignition that will feed the fire until removed. When the electrical supply has been isolated, the fire can be treated (generally) as ‘Class A’ for extinguishing purposes. However, you should always isolate the supply before fighting the fire; if this is not possible then a non-electrical conducting extinguishing agent is to be used regardless of the power status, on all occasions.Warning Note! - Some electrical equipment can store in capacitors, lethal voltages even if their power supply has been isolated. Always use extinguishers containing a non-electrical conducting extinguishing agent specifically designed for use on electrical equipment such as Carbon Dioxide (CO2) or Dry Powder.
High Temperature Cooking Oils
CLASS F: New class specifically dealing with high temperature ( 360°C) cooking oils used in large industrial catering kitchens, restaurants and takeaway establishments’ etc. Cooking oil fires, because of their high auto-ignition temperatures, are difficult to extinguish. Conventional extinguishers are not effective for cooking oil fires, as they do not cool sufficiently or may even cause flash back, thereby putting the operator at risk. These extinguishers contain a specially formulated wet chemical which, when applied to the burning liquid, cools and emulsifies the oil, extinguishing the flame, sealing the surface and preventing re-ignition.
European legislation dictates that all extinguishers have to have a Red body with an identifying label or band on it. The following colour codes apply:
WATER Red body with WHITE labelFOAM Red body with CREAM labelCO2 Red body with BLACK labelDRY POWDER Red body with BLUE label
Fire Extinguisher Colour Scheme
9 LTR WATER Red body with white labelling
Used on CLASS A fires involving solid materials such as paper, wood, solid plastics
Extinguishing method: COOLING & SMOTHERING
Do NOT use on Oil based fires, electrical fires or fires associated with electrical equipment.
Red body with a cream coloured identifying label or band
Used on CLASS B fires involving flammable liquids or liquefiable solids such as Petrol, Paint solvents
Extinguishing method:
Smothering
can also be used on class A fires
9 LTR FOAM
Red body with blue labelling
Used on All CLASSES of fires
(except chip or fat pan fires)
Extinguishing method: SMOTHERING
Dry Powder
STANDARD DRY POWDER knocks down flames. Best for liquids such as grease, fats, oil, paint, petrol (except chip or fat pan fires).
MULTI-PURPOSE DRY POWDER knocks down flames and, on burning solids, melts to form a skin smothering the fire. Provides some cooling effect.Best for wood, cloth, paper, plastics, coal etc. Fires involving solids. Liquids such as grease, fats, oils, paint, petrol etc (except chip or fat pan fires).
DangerThis type of extinguisher does not cool the fire very well and care has to be taken that the fire does not re-ignite. Additionally, although it is safe to use on live electrical equipment, it does not readily penetrate spaces inside the equipment and similar care has to be taken to ensure the fire does not re-ignite
The simplest method of which is usually to isolate the power supply.Smoldering material in deep seated fire such as upholstery or bedding can cause the fire to start up again.
Dry Powder
CARBON DIOXIDE (CO2)
Red body with a black coloured identifying band or label
Provided for use where fires could be started by electrical equipment
Extinguishing method:
SmotheringWARNING: Gas from CO2 extinguishers can be harmful if used in confined spaces as it displaces oxygen in the air. Ventilate the area as soon as the fire has been extinguished.
HOSEREELS
Red body with white labelling
Used on CLASS A fires involving solid materials such as paper, wood, solid plastics
Extinguishing method: COOLING & SMOTHERING
Do NOT use on Oil based fires, electrical fires or fires associated with electrical equipment.
FIRE BLANKET Red body case with white labelling- Blanket in side
Used on fires such as Chip or fat pan fires, persons on fire
Extinguishing method: SMOTHERING
Fire blankets are made of fire resistant materials. They are particularly useful for smothering fat pan fires or for wrapping round a person whose clothing is on fire.
Hold it well up in front of you by the top corners and keep your hands tucked in behind the blanket.
Place it over the fire and smother it.
Don't take it back off for at least half an hour! That will let the material cool down.
Turn off power source. i.e. Gas/Electric
Pull out the blanket from its case
Check the fire is smaller than the blanket.
How To Use:
FIRE BLANKET
Portable Fire Fighting Equipment
• Duration & Range of Discharge• 3KG= 6 seconds• 6 KG=9 seconds• 10KG= 12 seconds• > 10kg= 15 seconds (all timings approx)
• Range will vary check with manufactures data to ensure that you will not put the operator in danger by being too close to the seat of the fire
Portable Fire Fighting Equipment• Siting • On escape routes• Near to danger points (not too near that if required
you would increase the danger to the operator)
• Near to room exits (inside or out)
• Multi story buildings same location on each floor
• If possible in groups to form fire points• Travel no further than 30m to reach an
extinguisher• If possible in a wall recess handle about 1m
from floor (wall mounted) or on floor stands• Away from excesses of heat & cold
Portable Fire Fighting Equipment Maintenance
• Monthly Inspection- Located in proper place, if discharged, correct pressure, any obvious damage
• Annual Inspection & Maintenance- Thorough inspection, gas cartridges & replacement charges should be carried out by a competent person, may include internal & external inspection
• Test by discharge intervals of 5 years (co2 10 years)• British Standards recommendations
Portable Fire Fighting Equipment Training Requirements
• RRFSO 2005 does not specify training for fire extinguishers it does state “ Suitable & sufficient instruction & training on the appropriate precautions....to be taken by employee”
• Further requires training should be carried out periodically.
• Any person who may be called on to use a fire extinguisher should be trained in selection & practical use.
Passive Fire Fighting Systems
• Passive systems are either fully automatic or allow fire fighting to be done remotely
• Most are water systems but foam or gas may also be used
• Their action is primarily containment and minimising damage caused by fire spread
• Extinguishment is secondary
System Types
• Sprinklers• Water based system fully automatic or semi-
automatic• Deluge/Drenching
• Water or gas based system fully automatic or semi-automatic
• Ventilation/Smoke Control
Sprinklers
• Various types• Wet pipe, Dry pipe, Alternate
Pre-action.
• Siting and number depends on fire risk
Typical Components
How Sprinklers Work
• Head fits onto water pipe• Glass vial or bi-metal closure prevent operation• Heat causes breakage/release releasing water under
pressure• Deflector plate ensures spread & coverage
Drenchers
• Provides curtain of water to protect against radiant heat
• Only vulnerable structures need cover
• Fire resistance protects other structures
Drench in Action
Gaseous Systems
• Work by displacing air in workroom• Combustion cannot continue• Precautions required to prevent loss of life to occupants
INERGEN Storage
Ventilation/Smoke Control
• Not fire fighting as such
• Ventilation cut off to prevent fire spread
• Smoke removed to allow evacuation in breathable conditions
Effects of Smoke
Ventilation
Shopping Malls
Smoke Control of Common Escape Route in Flats
There should be some means of ventilating common corridors/ lobbies to control smoke and so protect common stairs
This offers individual protection to that provided by the fire doors to the stair
•Guidance on the design of smoke control systems using pressure differentials is available in BS EN 12101-6:2005.
B5 Access and Facilities
• The building shall be designed and constructed as to provide reasonable facilities to assist fire fighters in the protection of life.
• Reasonable provision shall be made within the site of the building to enable fire appliances to gain access to the building.
•Vehicle access for pump appliance within 45m of “all points”to blocks of flats
• Or: provide fire mains (not in f/f shaft)
•Fire mains
• New standard BS 9990
• Wet mains required for buildings over 50m
•Dry mains
• Access for pump within 18m
Fire Service Access
Fire Fighting Shafts/ Fire Mains
Private Fire Hydrants
Smoke Ventilators
Liaison with Fire Authority on Arrival
• Liaison established before emergency situation• Procedures implemented & staff trained (ensure enough
staff are available to carry out procedures(disabled evacuation etc)
• Information pack plans of buildings, info on fire alarm system, water supplies, gas/ electric shut off valve locations, build construction hazards (asbestos)
• Contents of building COSHH, acetylene• Out of hours procedures (emergency box location)