AND Case Studies of Recent Fires - NFEC · Case Studies of Recent Fires AND ... 151 29 25 16 43 84...

MAJ Lim Beng HuiHead Research & Analysis Br Fire Investigation UnitOperations Department

Overview of Fire Situation Overview of Fire Situation for 2008for 2008

Case Studies of Recent FiresCase Studies of Recent FiresANDAND

Fire StatisticsFire Statistics

Case Study 1Case Study 1 -- Dropped LightDropped Light

Case Study 2Case Study 2 -- Electrical OriginElectrical Origin

Case Study 3Case Study 3 -- Pure Oxygen HazardsPure Oxygen Hazards

Case Study 4Case Study 4 -- Dust Cloud ExplosionDust Cloud Explosion

ConclusionConclusion

SCOPESCOPE

Fire Incidents from Year 2004 to 2008

0100020003000400050006000

2004 2005 2006Year

No.

of F

ires

20

2007

4796

70008000

47024916 5039

Total Number of fires responded by SCDF

4973

2008

Breakdown of Fire Incidents from 2004 to 2008

0

50100150200250300

2004 2005 2006Year

20 197

2007

159

350400450500

152

311

152

340314 319

550 537473 471463

317

158

475

2008

Commercial & Industrial FiresN

o. o

f Fir

es

CommercialIndustrialTotal

Fire Injuries and Fatalities In Commercial & Industrial Fires

51015202530

40

20

60

28

3035404550

1

1213

4

34 32

30

Num

ber

of P

eopl

e

0

4343

0 2004 2005 2006Year

2007 2008 InjuriesDeathTotal

Causes of Fires in SingaporeIn 2007 and 2008

256136

411

299

599

524

28273071

453

615

265

313

0 500 1000 1500 2000 2500 3000 3500

Dropped Light

Electrical Origin

Overheating of Food

Naked Light

Incendiary

Others

Cau

ses

No. of Fires 2007 2008

Causes of Commercial & Industrial Fires

Breakdown of Fire Causes in 2007 and 2008

143

99

60

103

151

2925

16

43

84

19

49

49

75

0 20 40 60 80 100 120 140 160

Dropped Light

Overheated Food

Electrical Origin

Incendiary

Naked Light

Overheating of equipment

Sparks

Cau

ses

No. of Fires 2007 2008

OR THISOR THIS……....

OR EVEN THISOR EVEN THIS……....

SMOULDERING FIRESMOULDERING FIRE……• Under the right conditions, dropped light can

result in fires.

• May be smouldering for hours before ignition.

CASE STUDY 1CASE STUDY 1Basement Cark Park of Commercial BuildingBasement Cark Park of Commercial Building

99thth Jan 2009 (Friday) @ 1141 hrsJan 2009 (Friday) @ 1141 hrs

-- Fire believed to be caused by indiscriminate Fire believed to be caused by indiscriminate disposal of cigarette butts.disposal of cigarette butts.

-- Smoking ban imposed on all indoor Smoking ban imposed on all indoor public places since 1 Jan 09.public places since 1 Jan 09.

-- Smoking activities continue Smoking activities continue in inconspicuous places. in inconspicuous places.

THE FIRETHE FIRE

AIR PLENUM

CARPARK EXHAUST FAN ROOM

F(E) B3-1

F(E) B3-2

AREA OF ORIGIN

Fire involved items such as building materials, metal components, tiles, etc. stored inside the Air Plenum at basement 3 car park

Air Plenum

LAYOUT PLAN OF BASEMENT 3 CAR PARKLAYOUT PLAN OF BASEMENT 3 CAR PARK

AIR PLENUM

EXHAUST AIR SHAFT ABOVE


F(E) B3-1

F(E) B3-2

EXHAUST DUCT ROOM

Entrance into carpark

PARKING LOT

AREA OF ORIGIN

LAYOUT PLAN OF BASEMENT 1 CAR PARKLAYOUT PLAN OF BASEMENT 1 CAR PARK(direction of photos taken)(direction of photos taken)

AIR PLENUM


F(E) B3-1

F(E) B3-2

EXHAUST DUCT ROOM

ORIGIN AND CAUSE OF FIREORIGIN AND CAUSE OF FIRE

Cigarette butts found on the ground and inside the exhaust ducting at B1 car park

Believed that the cigarette butts were thrown down through B1 car park exhaust ducting vent and landed inside the Air Plenum at B3

The exhaust fan may have fan up the ignition source (lighted cigarette butts).

Basement 1 car park exhaust duct vent

Fire results in loss of business…

Safety Tips:Safety Tips:

•• Fully extinguishing cigarettes, joss Fully extinguishing cigarettes, joss sticks, incense papers, etc. after usesticks, incense papers, etc. after use

•• Proper disposal into ashtrays, incense Proper disposal into ashtrays, incense bins, etc. bins, etc.

•• Identify places where smokers may Identify places where smokers may light up and establish security and light up and establish security and safety patrols.safety patrols.

CASE STUDY 2CASE STUDY 2Workstation in Storeroom of Production PlantWorkstation in Storeroom of Production Plant

11stst Oct 2008 (Wednesday) @ 1250hrsOct 2008 (Wednesday) @ 1250hrs

-- Fire extinguished by SCDF before fire spreads Fire extinguished by SCDF before fire spreads to rubber productsto rubber products

-- Damage localized to the workstation.Damage localized to the workstation.

-- Fire believed to have originated from an Fire believed to have originated from an energized multienergized multi--extension socket. extension socket.

Line of Demarcation

Line of Demarcation

A

Line of Demarcation

A

Burn-through

Line of Demarcation

A

Severe Charring

Severely damaged electrical wirings and

fittings

A

Switch found to be in the ‘ON’ position.

Location of Main Switch where multi-extension socket was

plugged in

Why it may be a hazard?Why it may be a hazard?

1.1. Kept out of sightKept out of sight

2. Likely to be left on2. Likely to be left on

Other combustibles nearbyOther combustibles nearby


•• Do not overload power points.Do not overload power points.

•• Main switch Main switch ‘‘OFFOFF”” when not in usewhen not in use

CASE STUDY 3CASE STUDY 3 A

44--room HDB unit in Woodlandsroom HDB unit in Woodlands1212thth July 2008 (Saturday) @ 1242 hrsJuly 2008 (Saturday) @ 1242 hrs

-- Fire involved contents of an airFire involved contents of an air--con compressor con compressor (fire and explosion).(fire and explosion).

-- 1 person sustained burn 1 person sustained burn injuries to his hands injuries to his hands and legs.and legs.

LAYOUT PLAN OF UNITLAYOUT PLAN OF UNIT

N

NOT TO SCALE

CORRIDORSWITCHBOX

LIVING ROOM

BEDROOM 1

BEDROOM 2

MATTRESS

SWITCH

UNAFFECTED AIRCON

MASTERBEDROOM

UNAFFECTED AIRCON

KITCHEN

MATTRESS

STUDY TABLE

TOIL

ET

GASCYLINDER

REFRIGERANT

SOFA

THE AFFECTED AIRCON

DETAILS OF INCIDENTDETAILS OF INCIDENT

• Contractor was performing a pressure test on the air-con compressor to test for leakages. The gas used was pure oxygen from a cylinder (verified by HSA)

• Sudden explosion heard and 1 worker sustained burn injuries.

• Secured by personal safety line and did not fall off.

CASE STUDY 3CASE STUDY 3 BOnboard a Docked Vessel in Onboard a Docked Vessel in TuasTuas88thth June 2008 (Sunday) @ 1151 hrsJune 2008 (Sunday) @ 1151 hrs

-- Fire involved contents of pipelines on a ship.Fire involved contents of pipelines on a ship.

-- The pipelines (for delivering The pipelines (for delivering hydraulic oil) had to be hydraulic oil) had to be tested to a specified tested to a specified pressure. pressure.

-- 6 workers sustained burn 6 workers sustained burn injuries.injuries.

DAMAGE SUSTAINED:

Hydraulic controls damaged Ruptured hydraulic pipes

Heat damage to insulation inside big generator room

DAMAGE SUSTAINED:

Battery inside room sustained heat damage

Ruptured pipes and burnt insulation

Place where soap test carried out. Explosion witnessed by workers here


• Pressure Test (140 bar) on pipes

• Usage of pure oxygen from manifold system

• Whilst workers were administering a soap test (about 10 minsfrom initiation of oxygen), a loud explosion occurred. 6 workers sustained burn injuries

COMPRESSED OXYGEN

MANIFOLD SYSTEM

MANIFOLD SYSTEM CONNECTED TO THE HYDRAULIC PIPES


• Piping broke off at various joints.

• Pipe ends observed to have ‘opened up’ suggesting the fire occurred from within the pipes.

ORIGIN AND CAUSEORIGIN AND CAUSE

• Pure Oxygen is an oxidising gas which can vigorously accelerate combustion.

• Presence of lubricating grease and rust were found in the pipes.

• Equipment and material contaminated with oil or grease can ignite easily and burn with explosive violence in oxygen-enriched atmospheres.


•• Never use pure Oxygen for pressure Never use pure Oxygen for pressure and leakage tests.and leakage tests.

•• Common market practice to use inert Common market practice to use inert gases, such as Nitrogen, which gases, such as Nitrogen, which eliminates Oxygen from the triangle of eliminates Oxygen from the triangle of fire.fire.

CASE STUDY 4CASE STUDY 4Creamer Making PlantCreamer Making Plant

2424thth May 2009 (Sunday) @ 1036hrMay 2009 (Sunday) @ 1036hr

-- Company acquired machine approx. 8 months Company acquired machine approx. 8 months back. back.

-- Upped the operating temp (within operating Upped the operating temp (within operating range) to increase output approx. 1 week back.range) to increase output approx. 1 week back.

Schematic of Creamer making Machine

DAMAGE SUSTAINED:

Partition walls cracked. Machine panels dislodged.

False ceiling fell.

DAMAGE SUSTAINED:

Explosion hatches blown out. Filters burnt and damaged.

Machine sustained heat damage.Ventilation panels fell off.

Schematic of Creamer-making Machine

Witness Account:

Was topping up freeflow agent when there was an explosion at this location.

Saw flames shooting out sideways

Closed-Up View of Area of ‘Explosion’

Spray dryer

Fluid bed

Remains of Silicon Sheet which connects the spray-dryer to the fluid bed.

Dust Cloud ExplosionsDust Cloud ExplosionsDust clouds of finely powdered substances can become Dust clouds of finely powdered substances can become combustible or explosivecombustible or explosive. When there is a static . When there is a static discharge in a dust or vapor cloud, explosions have discharge in a dust or vapor cloud, explosions have occurred. Among the major industrial incidents that occurred. Among the major industrial incidents that have occurred are: a have occurred are: a grain silo grain silo in southwest France, a in southwest France, a paint plant in Thailand, a factory making paint plant in Thailand, a factory making fiberglassfiberglassmouldingsmouldings in Canada, a storage tank explosion in in Canada, a storage tank explosion in Glenpool, Glenpool, Oklahoma in 2003, and a portable tank Oklahoma in 2003, and a portable tank filling operation and a tank farm in filling operation and a tank farm in Des Moines, Des Moines, Iowa Iowa and and Valley Center, KansasValley Center, Kansas in 2007. in 2007. [1] [2] [3] [1] [2] [3]

[1] [1] Hearn, Graham (1998). "Static electricity: concern in the Hearn, Graham (1998). "Static electricity: concern in the pharmaceutical industry?". pharmaceutical industry?". Pharmaceutical Science & Technology TodayPharmaceutical Science & Technology Today 11 (7): (7): 286286––287. 287. doi:10.1016/S1461doi:10.1016/S1461--5347(98)000785347(98)00078--9. 9. [2] [2] [http://www.ntsb.gov/publictn/2004/PAR0402.pdf [http://www.ntsb.gov/publictn/2004/PAR0402.pdf Storage Tank Storage Tank Explosion and Fire in Glenpool, Oklahoma] April 7, 2003 Explosion and Fire in Glenpool, Oklahoma] April 7, 2003 National National Transportation Safety Board Transportation Safety Board [3] [3] Static Spark Ignites Flammable Liquid during Portable Tank FilliStatic Spark Ignites Flammable Liquid during Portable Tank Filling ng Operation Operation October 29, 2007 October 29, 2007

Conditions Necessary for Static Arc IgnitionConditions Necessary for Static Arc Ignition1. There must be an effective means of static

charge generation

2. There must be a means of accumulating and maintaining a charge of sufficient electrical potential

3. There must be a static electrical discharge arc of sufficient energy

4. There must be a fuel source in the approximate mixture with minimum ignition energy less than the energy of the static electric arc.

5. The static arc and fuel source must occur together in the same place and at the same time.

- NFPA 921


charge generation

““The The flowing movement of finely powdered substancesflowing movement of finely powdered substancesor low conductivity fluids in pipes or through or low conductivity fluids in pipes or through mechanical agitation mechanical agitation can build up static electricitycan build up static electricity. .

-- Wagner, John P.; Wagner, John P.; ClavijoClavijo, Fernando Rangel [doi:10.1016/S0304, Fernando Rangel [doi:10.1016/S0304--3886(00)000193886(00)00019--X Electrostatic charge generation during impeller mixing X Electrostatic charge generation during impeller mixing of used transformer oil] Department of Nuclear Engineering, Safeof used transformer oil] Department of Nuclear Engineering, Safety ty Engineering and Industrial Hygiene Program, Engineering and Industrial Hygiene Program, Texas A&M UniversityTexas A&M University, , College Station, online 21 August 2000; accessed in Jan 2009College Station, online 21 August 2000; accessed in Jan 2009


charge generation

Generation of a static charge can happen during Generation of a static charge can happen during handling and processing of dusts and fibers in handling and processing of dusts and fibers in industry. Dust dislodged from a surface or created by industry. Dust dislodged from a surface or created by the the pouring or agitation of dustpouring or agitation of dust--producing materialproducing material, , such as grain or such as grain or plverizedplverized material, material, can result in the can result in the accumulation of a static chargeaccumulation of a static charge on any insulated on any insulated conductive body with which it comes into contactconductive body with which it comes into contact

-- NFPA 921NFPA 921

Conditions Necessary for Static Arc IgnitionConditions Necessary for Static Arc Ignition2. There must be a means of accumulating and

maintaining a charge of sufficient electrical potential.

-- Actual silicone and Actual silicone and creamer used in creamer used in experiment experiment

Silicone Sheet

Electrostatic meter registering a negative

charge

Conditions Necessary for Static Arc IgnitionConditions Necessary for Static Arc Ignition3. There must be a static electrical discharge arc of

sufficient energy

No means of testing at this point in time.No means of testing at this point in time.

Local forensic labs unable to support.Local forensic labs unable to support.

Static discharge is difficult to prove.Static discharge is difficult to prove.

Conditions Necessary for Static Arc IgnitionConditions Necessary for Static Arc Ignition4. There must be a fuel

source in the approximate mixture with minimum ignition energy less than the energy of the static electric arc.

3 nozzles sprays a fine mist of liquid creamer mixture.

SPRAY DRYER

Mist dries up as it settles in the heated spray dryer

Creamer powder being channelled into fluid bed.

Conditions Necessary for Static Arc IgnitionConditions Necessary for Static Arc Ignition


-- Actual creamer used in experiment.Actual creamer used in experiment.-- Cloud of falling creamer is a potential fuel source Cloud of falling creamer is a potential fuel source



-- Witness was introducing Witness was introducing freeflowfreeflow agent at the agent at the material time.material time.

-- Possibility of Possibility of freeflowfreeflow agent igniting as it falls?agent igniting as it falls?


5. The static arc and fuel source must occur together in the same place and at the same time.

Machine is earthed

Fuel: Falling dry creamer powder within.

Possible ignition source:Static discharge from silicone sheet

Vibrating fluid bed to move creamer down the processing line

Literature reviews and experiments have shown that:• Static charge can be generated.

• Silicone sheet can allow charges to accumulate.

• Dry creamer cloud is a possible fuel source.

Creamer sent for forensic analysis:Higher operating temp. may have resulted in finer creamer particles i.e. more susceptible to ignition


•• Conducting a risk assessment on new Conducting a risk assessment on new processes may help to identify processes may help to identify potential weaknesses (hazards).potential weaknesses (hazards).

•• Guidelines available on MOM website:Guidelines available on MOM website:

http://www.mom.gov.sg/publish/momportal/en/communities/workplace_safety_and_health/maintaining_a_safe_workplace/occupation_safety/risk_management.html

Risk Assessment GuidelinesRisk Assessment Guidelines

CONCLUSIONCONCLUSION

•• Be conscientious about fire safety.Be conscientious about fire safety.

-- Indiscriminate disposal of cigarette butts, etc.Indiscriminate disposal of cigarette butts, etc.-- ‘‘OFFOFF’’ electrical switches.electrical switches.-- Check on the use of proper materials in work Check on the use of proper materials in work

processes.processes.-- Conduct risk assessments, where appropriateConduct risk assessments, where appropriate

•• Together, we can prevent fires.Together, we can prevent fires.

End of PresentationEnd of PresentationThank you for your attention.

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