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FIRE SAFETY

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FIRE SAFETY NEBOSH Certificate FIRE SAFETY - Aims to minimise consequences of fires PREVENTION make sure fires don t start PRECAUTIONS minimise the damage from fire ... – PowerPoint PPT presentation

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Title: FIRE SAFETY


1
FIRE SAFETY
  • NEBOSH Certificate

2
FIRE SAFETY - Aims to minimise consequences of
fires
  • PREVENTION
  • make sure fires dont start
  • PRECAUTIONS
  • minimise the damage from fire
  • PROCEDURES
  • action to take in the event of fire

3
HAZARDS OF FIRE
  • flames and heat
  • toxic/combustible smoke and gases
  • structural failure of buildings
  • oxygen depletion

4
FIRE TRIANGLE - principles of combustion
5
Sources of fuel
FLAMMABLE SOLID
FLAMMABLE LIQUID
FLAMMABLE GAS
OXIDISING AGENT
6
SOURCES OF IGNITION - examples
  • Radiant or convected heat from heaters
  • friction
  • hot surfaces
  • chemical
  • sparks
  • smoking
  • electricity static or mains
  • internal combustion engines
  • tools
  • Flame

7
Principles of heat transmission and fire spread
convection
radiation
conduction
8
Spread of fire
  • Conduction - spread of heat energy through
    solids
  • Convection - heat transfer through a fluid or
    gas, involving expansion and movement
  • Radiation - emission of heat energy through
    electromagnetic radiation in the infra-red part
    of the spectrum, which is then absorbed by matter
    to varying degrees

9
Extinction of fires
  • Remove one element or more of fire triangle, by
  • starving it of fuel
  • smothering it to exclude oxygen
  • cooling it to reduce temperature.
  • Fire-fighting revolves around these principles

10
Causes of fires
  • Arson
  • discarded cigarettes and matches
  • faulty plant equipment
  • flammable liquids materials storage use
  • hot processes
  • heating appliances
  • combustible wastes
  • Arson accounted for 41 of the 43,600 fires
    that occurred in non domestic premises in
    1999 source Home Office

11
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12
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13
Art School molotovs
14
Elements of fire prevention and control
15
Interaction of fire legislation
16
The Building Regulations 1991 Approved Document
B Fire safety
  • Covers means of escape internal fire spread
    (linings and structure) external fire spread
    access and facilities for the fire service.
  • Requirements do not apply retrospectively, but
    will apply to new buildings, or modifications,
    etc to existing buildings

17
BS5588 parts 1 11Fire precautions in the
design, construction and use of buildings
  • Escape routes horizontal and vertical
  • Number of escape routes
  • Travel distances within each storey
  • Width of exits and escape routes
  • Number of persons per floor
  • Fire compartmentation
  • Fire resistance

18
BS5588-111997 Escape distances
19
Fire compartmentation in buildings
Fire escape route from various rooms
are protected.
office
laboratory
classroom
Office and classroom similar level of risk no
barrier.
Classroom protected from higher fire risks in
laboratory.
20
Means of escape
  • A route that can be followed by an occupant,
    unaided or without risk from fire, that will lead
    to safety
  • clear marking of route, HSafety (Signs
    Signals) Regs 1996 BS 5499 1990 Fire safety
    signs, notices and graphic symbols, parts 1 3

21
Escape 2
  • Calculated Time available for escape greater
    than Time needed for escape
  • time available calculated on assessment of time
    from fire start and its making escape route
    unsafe
  • time taken for everyone to evacuate once the fire
    has been discovered warning given.
  • More than one route - 25m(HR), 32m(Norm sleeping
    area), 45m(NR), 60m(LR)
  • One route - 12m(HR), 16m(NR sleeping), 18m(NR
    except factories), 25m(incl. Factories), 45m(LR).

22
Escape 3
  • Protected and unprotected zones
  • Escape distances 18m hazardous processes, 45m
    offices
  • Fire compartments
  • Fire doors - self-closers, smoke seals, etc

23
Number width of exits - Escape 4
  • There should be enough available exits of
    adequate width, from every room, storey or
    building. Adequacy is assessed on
  • doorways min. width 0.75m for upto 40
    people/minute
  • doorways min. width 0.8m for wheelchair users
  • doorway min. width 1m for upto 80 people/minute
  • where more than 80 people/minute need to escape,
    the min. width should be increased by 0.075m for
    every additional 15 people.
  • Calculate above on the people in the building
    divided by the time available for escape

24
Building fabric - Building Regs 1991, Approved
Document B
  • 0.5 or 1 hour fire resistance of doors, walls and
    ceilings materials from which escape routes
    constructed
  • Fire resistance of load bearing elements of
    structure
  • Compartmentation, to reduce spread of fire,
    complementary to construction of escape routes
  • Other - external fire spread, fire service
    access, ventilation

25
EVACUATION PROCEDURE - the recommended order of
business
  • 1. evacuate the building by the fastest route
  • 2. sound the fire alarm
  • 3. call the fire brigade
  • 4. assemble at the designated location

26
FIRE DRILLS
  • legal requirement
  • effective means of escape
  • training exercise
  • practice evacuating the building by the fastest
    route and use of assembly points
  • test emergency procedures
  • role of fire marshals to aid evacuation and
    prevent re-entry

27
Fire Precautions Act 1971
  • All premises meeting certain criteria must have a
    valid fire certificate
  • hotels, boarding houses gt 6 people, or bedrooms
    above/below ground floor
  • workplaces, ie. Factories, OSRP premises
  • 20 in workplace at one time, or
  • 10 above ground floor, or
  • explosives or HFs stored or used
  • Cert. Issued subject to adequacy of escape
    routes, alarm systems, fire fighting equipment,
    etc

28
Fire Precautions (Workplace) Regs 1997 (99)
  • Require provision and maintenance of measures to
    detect, fight and warn of fires, ensure safe
    evacuation
  • Now, with MHSWR, require FRAs for premises
  • Revising FRAs ensures steady improvement, and
    covers buildings not included in FPA 71 and fire
    certificates

29
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30
Building management of fire risks
  • Good housekeeping by those responsible for
    managing buildings is a combination of
  • Following fire risk assessment/Fire Certificate
    recommendations
  • Constructing compartments, fire escape routes,
    and installing fire detection and alarm systems
    as necessary
  • Reducing potential for fuels and ignition sources
    to mix
  • Maintaining readiness to evacuate safely through
    organising staff, instruction and training,
    conducting fire drills and reviewing performance
    of people and systems.

31
BS 5839, part12002 - Fire detection and alarm
systems
  • Manual - ie. People, who trigger the alarm system
    by activating a break-glass
  • Automatic - detectors placed carefully and
    sensitive to heat, smoke or combustion products

32
BS5839 part 1 2002 Fire detection and fire
alarm systems for buildings
  • Purpose of fire alarm systems protection of
    life and property
  • System categories
  • M Manual systems
  • L 1 5 incorporate automatic fire detection to
    some degree, for the protection of Life
  • P 1 2 incorporate automatic fire detection to
    protect Property.

33
Fire alarms
  • Triggered by automatic smoke or heat detectors or
    person activating a break-glass
  • Audible warning, klaxon or bell (can also be
    visual flashing lights for deaf, or vibrating
    pagers for deaf/blind)
  • can be shouting fire! or hand-bell in small
    premises
  • Detection alarm systems to comply with BS5839
    part 1

34
Classification of Fires - BS EN 2
  • A - Free burning materials, paper, wood, plastics
    etc.
  • B - Flammable liquids, petrol, meths, solvents
    etc.
  • C - Flammable gases, methane, hydrogen etc.
  • D - Metals, potassium, sodium, magnesium etc.
  • Electricity can be involved in any class of fire

35
Water extinguishers
Red body Suitable for use on Class A Fires, wood
and paper etc. Not suitable for combustible
liquids, cooking fats etc. Not safe to use on
fires involving electricity Extinguishes by
cooling
36
Foam extinguishers
Cream body (Old type) or Red Body with Cream
label. Suitable for Class A and B Fires. Not
suitable for use on fires involving electricity
Extinguishes by cooling and sealing the surface
of a burning liquid.
37
Powder extinguishers
Blue body (Old type) or Red body with blue
label. Best on Class B fires but safe to use on
any type of fire. Works by chemically interfering
with the combustion reaction
38
Carbon dioxide CO2 extinguishers
Black body (Old type) or red body with black
label (New type). Best on Class B and C fires but
safe to use on any type of fire Safe to use on
fires involving electricity Extinguishes by
reducing oxygen levels and cooling.
39
Other fire fighting equipment
  • Hose reels
  • Fire blankets
  • Automatic sprinklers
  • Carbon dioxide/Halon systems
  • Drenchers

40
HFL LPG Regs - definitions
  • HFLs - flashpoint (below 32o C) and
    combustibility. Test methods in schedules 1 2
    of Regs.
  • LPG - commercial butane, commercial propane, or
    combinations thereof.

41
Storage
  • Suitable fixed storage tanks in safe positions
    suitable closed vessels in open air and protected
    from direct sunlight or closed vessels in
    storerooms in safe position or fire resisting
    structure or in workroom in fire resisting
    cupboard which is fire resisting structure.

Marking
  • Every storeroom, cupboard, bin, tank, and vessel
    used for storing HFLs should be clearly and
    boldly marked Highly Flammable or Flashpoint
    below 32oC
  • Where this is impracticable, such a warning is to
    be placed as near to storage as possible.

42
Precautions against spills and leaks
  • Conveyed through factory in vessels designed to
    prevent spills.
  • Process use to be kept as low as r.p.
  • Steps taken to prevent storage tanks from
    leaking.
  • Spills should be drained off to a safe place.

Sources of ignition
  • No ignition sources shall be present where a
    dangerous concentration of vapours from hfls is
    expected to be present.

43
Example references
  • Fire Precautions Act 1971
  • Fire Precautions (Workplace) Regulations 1997 as
    amended
  • Building Regulations 1991, Approved Document B
    Fire Safety not retrospective
  • BS5588 Fire precautions in the design,
    construction and use of buildings parts 1-11
  • BS5839 pt 12002 Fire detection and alarm
    systems for buildings
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