Presentation on theme: "Siting of Hazardous Industries – Role of Risk Analysis"— Presentation transcript:
1Siting of Hazardous Industries – Role of Risk Analysis Capacity Building Programme on“New Techniques and Strategies in Prevention and Management of Industrial Disasters”to the Karnataka Factory Inspectorate Oct 2010Siting of Hazardous Industries – Role of Risk AnalysisDr. A. Koshy Oct 2010, Bengaluru, KarnatakaORGANIZERSKarnataka State Safety Institute®Department of Factories, Boilers, Industrial Safety & Health, BengaluruSPONSORSDisaster Management Institute
2Concerns and issues in Siting/ Layout Strategic Principles in the determination of safe location and layout for a new or a expansion projectKey information to be considered before selecting a site locationHow are siting issues managed when limited space is available?How are security concerns in a new site addressed ?Explain Siting and LayoutIndustrial dev comes price
3An Ideal SituationA site location and layout that will minimize risk to the surrounding and community/ personnel and property while maximizing the ease of safe operation and maintenance.Appropriate siting and layout establishes a foundation for a safe and secure operation.Eg BPCL LPG sites established in and ( Policy in acquiring appropriate land )Basis for Facility Siting and LayoutBuilding a new site or adding equipment to an existing one is often an exciting, but daunting, proposition. If it is done well, capital is well invested, goals are met, and the future looks promising. If it is done poorly, money may be wasted, goals unachieved, and the future could be unwittingly compromisedAppropriate siting and layout establishes a foundation for a safe and secure site. A site that is well laid out will have a lower risk level than a poorly laid out site. The potential for toxic impacts, fire escalation, and explosion damage will be lower. The risk to personnel and the surrounding community will be reduced. Additionally, maintenance will be easier and safer to perform. However, these benefits do not come without associated costs. Separation distances translate to real estate that costs money. Tradeoffs between initial capital investment, life cycle costs, and risk reduction are inherent in siting and layout decisionssite location and layout that will minimize risk to site and community personnel and property while maximizing the ease of safe operation and maintenance. This approach may reduce the total life cycle cost.
4Hazard Management in Life Cycle of an Engineering Project Site Lay-out of installationEmploying HAZID early in Project cycleUnderstanding the hazards is the first stepConsists of three partsHazards of MaterialsProcess Design BasisEquipment Design Basis
5Hazard Techniques for Site evaluation Techniques of Fire Explosion Index and Toxicity IndexDow’s IndexMond’s IndexCodes ( OISD)Allowing objective spacing distances to be taken into account at all stages
6Major Accident Hazard Group “Major accident” means an incident involvingloss of life inside or outside the site or 10 or more injuries inside and / or one or more injuries outside orrelease of toxic chemical or explosion or fire or spillage of hazardous chemicals resulting in ‘on-site’ or‘off-site’ emergencies or damage to equipment leading to stoppage of process or adverse effects to the environment.THE MAJOR ACCIDENT HAZARD CONTROL RULES, 1997Major accident means an ‘Uncontrolled Occurrence’ in the operation of a site which leads to severe or catastrophic consequences to people, assets, the environment and/or company reputation.The consequences may be immediate or delayed and may occur outside as well as inside the site. There will also be a high potential for escalation.Examples :loss of containment of flammable and/or toxic fluids leading to fire, explosion and/or toxic injuryevents resulting in structural failure which could lead to further progressive collapseloss of stability of mobile offshore installationwell blowoutsTransport vessels colliding with installations used for bulk loading explosive, flammable or toxic substances.service vessel colliding with or otherwise affecting offshore installationsother external hazards affecting offshore and onshore sites e.g. accommodation/work barges alongside fixed installations, helicopters and aircraft, road/marine product tankersThe definition of ‘Major Accident’ specifically excludes ‘Occupational Accidents’ which have bounded, albeit possibly severe or catastrophic consequences. This means that one or more pedestrian fatalities resulting from a road accident on a site (however regrettable and tragic) would not be defined as a ‘Major Accident’. Similarly, one or more fatalities resulting from a fall from a scaffolding platform (again regrettable and tragic) would not be defined as a ‘Major Accident’
7Features of Well Laid out Site The potential for toxic impacts, fire escalation, and explosion damage will be low.The risk to personnel and the surrounding community will be reduced.Maintenance will be easier and safer to perform.However, these benefits do not come without associated costs.Separation distances translate to real estate that costs money.
8Some key industrial accidents Flixborough (6/74) 28 fatalities - $167MMSeveso (7/76) Contaminated countrysideMex. City (11/84) 550+ fatalities - $26MMBhopal (12/84) 3M+ fatalities - 200M affectedChernob. Nuc. Plt. (4/86) 31 fatalities mi2 evacuatedPiper Alpha Plat. (7/88) 165 fatalitiesPasadena, Tx. (11/89) 23 fatalities - $797MMChannelview, Tx. (7/90) 17 fatalities - $14MMPemex, Mexico (7/96) Multiple fatalities - $253MM, $8MMM loss to economyPetrobras, Brasil (6/2001) fatalities - $300MMToulouse, France (9/01) 29 fatalities, 20,000 homes damaged* Large property damage losses (17th edition); M&M Protection Consultants; 1166 Avenue of the Americas, NY, NY
9Hazard & Risk Assessment IDENTIFYAre people exposed to harm resulting from the company’s operations?ASSESSWhat are the causes, consequences & effects?How likely is the loss of control?What is the risk & is it ALARP?CONTROLCan the causes be eliminated?What controls are needed & can they be effective?RECOVERCan the potential consequences & effects be mitigated?What are the recovery measures required?Are the recovery capabilities suitable & sufficient?
10Explosion at Chemical facility Flixborough, England, 1974
11Explosion at Chemical facility Flixborough, England, 1974 A large quantity of cyclohexane vapor was released when a 20” “makeshift” bypass pipe rupturedThe cyclohexane formed a flammable mixture and subsequently found a source of ignition.The resulting massive vapor cloud explosion killed 28 workers, injured (Minimized as the office block was unoccupied)At the Nypro(UK) site,Accident summaryAt about 16:53 hours on Saturday 1 June 1974 the Nypro (UK) site at Flixborough was severely damaged by a large explosion. Twenty-eight workers were killed and a further 36 suffered injuries. It is recognised that the number of casualties would have been more if the incident had occurred on a weekday, as the main office block was not occupied. Offsite consequences resulted in fifty-three reported injuries. Property in the surrounding area was damaged to a varying degree.Prior to the explosion, on 27 March 1974, it was discovered that a vertical crack in reactor No.5 was leaking cyclohexane. The plant was subsequently shutdown for an investigation. The investigation that followed identified a serious problem with the reactor and the decision was taken to remove it and install a bypass assembly to connect reactors No.4 and No.6 so that the plant could continue production.During the late afternoon on 1 June 1974 a 20 inch bypass system ruptured, which may have been caused by a fire on a nearby 8 inch pipe. This resulted in the escape of a large quantity of cyclohexane. The cyclohexane formed a flammable mixture and subsequently found a source of ignition. At about 16:53 hours there was a massive vapour cloud explosion which caused extensive damage and started numerous fires on the site.Eighteen fatalities occurred in the control room as a result of the windows shattering and the collapse of the roof. No one escaped from the control room. The fires burned for several days and after ten days those that still raged were hampering the rescue work.
12Damages ( Onsite and Offsite) 18 fatalities occurred in the control room as a result of the windows shattering and the collapse of the roof.No one escaped from the control room.Fires burned for several days and after ten days those that still raged were hampering the rescue work.Offsite consequences reported injuries.Property in the surrounding area was damaged to a varying degree.
13Contributing Factors Plant layout - position of occupied buildings Not following codes & operating procedures while introducing modificationsdesign codes, management of change procedures, maintenance procedures during recommissioningPlant layout - position of occupied buildingsControl Room not designed for withstanding major hazardsEmergency plan not updated following modificationsUK COMAH regulation was introducedFailings in technical measuresA plant modification occurred without a full assessment of the potential consequences. Only limited calculations were undertaken on the integrity of the bypass line. No calculations were undertaken for the dog-legged shaped line or for the bellows. No drawing of the proposed modification was produced.Plant Modification / Change Procedures: HAZOPDesign Codes - Pipework: use of flexible pipesNo pressure testing was carried out on the installed pipework modification.Maintenance Procedures: recommissioningThose concerned with the design, construction and layout of the plant did not consider the potential for a major disaster happening instantaneously.Plant Layout: positioning of occupied buildingsControl Room Design: structural design to withstand major hazards eventsThe incident happened during start up when critical decisions were made under operational stress. In particular the shortage of nitrogen for inerting would tend to inhibit the venting of off-gas as a method of pressure control/reduction.Operating Procedures: number of critical decisions to be madeInerting: reliability/back-up/proof testing
15Explosion at Refinery, Pasadena, Texas 23 Oct 1989
16Explosion at Refinery, Pasadena, Texas 23 Oct 1989 During maintenance work on a reactor settling leg, a large release of flammable vapor occurred at the Phillips 66 chemical complex.The result -- a massive vapor cloud explosion, followed by a series of further explosions and fires.23 fatalities and 300 people injured. Extensive damage to the plant facilitiesMetal & Debris as far as KmAccident summaryAt approximately 1:00 p.m. on the 23rd October 1989 Phillips’ 66 chemical complex at Pasadena, near Houston (USA) experienced a chemical release on the polyethylene plant. A flammable vapour cloud formed which subsequently ignited resulting in a massive vapour cloud explosion. Following this initial explosion there was a series of further explosions and fires.The consequences of the explosions resulted in 23 fatalities and between 130 – 300 people were injured. Extensive damage to the plant facilities occurred.The day before the incident scheduled maintenance work had begun to clear three of the six settling legs on a reactor. A specialist maintenance contractor was employed to carry out the work. A procedure was in place to isolate the leg to be worked on. During the clearing of No.2 settling leg part of the plug remained lodged in the pipework. A member of the team went to the control room to seek assistance. Shortly afterwards the release occurred. Approximately 2 minutes later the vapour cloud ignited.
17Contributing FactorsSite and industry standards for maintenance not followedTraining and competenceWork permit system - contractorsPositioning of occupied buildingsFailings in technical measuresBoth the company and industry safety required isolation by means of a double-block system or the use of blind flange. However, at a plant level a procedure had been adopted which did not comply with this.Maintenance Procedures: isolationThe accident investigation established that the single isolating ball valve was actually open at the time of the release. The air hoses to the valve had been cross-connected so that the air supply that should have closed the valve actually opened it.Maintenance Procedures: recommissioningSite procedures laid down details that air hoses to valves were to be disconnected prior to maintenance work. This task was not carried out.Maintenance Procedures: training/competence, management/supervisionThe site held a large inventory of flammable materials under high pressure yet it had no fixed gas detection system.Leak / Gas Detection: positioning of detectorsVentilation intakes of buildings close to or downwind of the process plant were not arranged so as to prevent the intake of gas in the event of a release.Plant Layout: positioning of occupied buildingsAn effective permit to work (PTW) for both company employees and contractors was not enforced by the company.Permit to Work Systems: working in hazardous areasThere was no dedicated fire water system. Firewater was drawn off from the process water system. This system was severely damaged in the explosions resulting in a loss of water pressure. The fire water pumps failed when the raging fires attacked their electrical supply cables. Of the three standby diesel pumps units, one was under maintenance and another ran out of fuel.Active / Passive Fire Protection: testing and inspectionSome concern was expressed as to the audible level of the emergency alarm. It was likely that individuals in certain parts of the plant were unable to hear the siren.Warning Signs: human factorsThe intended control centre was damaged beyond use and telephone communications disrupted.Emergency Response / Spill Control: site emergency planThe location of the control room, separation distances between plant and escape routes (particularly for administrative staff) were all criticised.Plant Layout: position of occupied buildings
18Risk Factors in Site Selection Risk to Population density around the site( from choice hazardous material, equipment , activites)Risk from Natural disaster occurrence (earthquake, flood, etc.)Risk of non-availability of power, steam and waterHAZID reportAir, water and waste regulations and their complexityAccessibility to raw materials and marketsTransportationSiting permits and complexity of obtaining themInteraction requirements in industrial developmentsLabour availability and costsInvestment incentives
20Plant Siting Safety Considerations Buffer zoneLocation of other hazardous installations in vicinityInventory of toxic and hazardous materialsAdequacy of firefighting water supplyAccess to Emergency equipmentAvailability of emergency response support from adjacent industries and the communityWeather extremes and prevailing windsLocation of highways, waterways, railroad and airplane corridorsEnvironmental and waste disposal restrictions during emergenciesDraining and grade slopeMaintenance and inspectionPrevailing winds and meteorological data
22Critical Radiation Levels The dosage - response relation can be expressed by probit equationY = ln (t.I4/3) for lethalitywhere Y is the probit; t is the time (s) and I is the radiation heat intensity (W/m2)The radiation intensities can be expressed as 1%, 50% and 99% fatality levels, using the duration and dosage relationship from the above equation.
23Damage Criteria for Explosion Over pressure (bar)Type of damage0.30Heavy0.20 to 0.27Rupture of Oil storage tanks Possibility of damage to eardrums (Human)0.20Steel frame constructions distorted and pulled away from foundations0.10Repairable damage0.03Large & small windows usually shattered0.0210% window glass broken0.01Crack of windows
27Toxic Dispersion & Effects Vapor clouds may give rise to large fires, explosions or toxic effects.Other things being equal, toxic gas clouds are likely to be dangerous at much greater distances from the point of release than their flammable counterparts.Dispersion is the process through which gases can travel long distances.Two types of dispersion occur in industrial situations.
28Types of Dispersion Dispersions Dense Neutral A distinction between different types of dispersion is made for the use of suitable models. It is based on the type of material
29Consequences from Toxic Gas Dispersion A large toxic release may give rise to the following effects on human beings:lethal injurynon-lethal injuryIrritationToxic gas releases may cause domino effects by rendering adjacent plants inoperable and injuring operators.Prevention/mitigation by provision of automatic control systems using inherently safer principles and a suitable control room
30Large Toxic Release The main mode of exposure is inhalation The effects of a toxic release are estimated knowing the relationship between the concentration-time profile and the degree of injuryThe product C of concentration and the time of exposure t, is called dosage and is directly calculated from the dispersion equation
31Exposure LimitsThree agencies provide information regarding exposure limits, specifying safe levels of air borne contaminantsOSHAThe National Institute of Occupational Safety (NIOSH) andThe American Conference of Governmental Industrial Hygienists (ACGIH)These 3 agencies have established guidelines and specific exposure levels of various contaminantsThe greatest danger of overexposure to hazardous materials occurs through inhalation. Because of this, three agencies provide information regarding exposure limits, specifying levels of air borne contaminants that are considered safe. OSHA has established a list of 425 substances that are considered air contaminants, many of which are commonly found in the research lab. Each of these materials has associated with it a PEL or permissible exposure limit. In addition, there are two other authorities interested in measuring air contaminants - the National Institute of Occupational Safety (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH). These 3 agencies have established guidelines and specific exposure levels of various contaminants. The levels recommended by these agencies should be used as guidelines, and in addition, the PELs established by OSHA are considered legal limits with the power of the legal system behind them.
32Protection from Domino/ Cascade Effects Arranging separation distances such that damage to adjacent plants will not occur even in the worst case;Provision of barriers e.g. blast walls, location in strong buildings;Protecting plant against damage; e.g. provision of thicker walls on vessels;Directing explosion relief vents away from vulnerable areas; e.g. other plants or buildings, roadways near site boundaries.However, these measures may not provide practical solutions against missiles, and risk analysis may be required to prove adequate safety.
33LPG Terminal Mexico City, Mexico 1984 A major fire and a series of catastrophic explosions occurred at the PEMEX LPG Terminal.After the intial release, the first BLEVE occurred.For the next 90 minutes, a series of BLEVEs followed as other LPG vessels violently exploded.Approximetly people were killed and the facility was destroyed.PEMEX LPG Terminal, Mexico City, Mexico. 19th November 1984A drop in pressure was noticed in the control room and also at a pipeline pumping station. An 8-inch pipe between a sphere and a series of cylinders had ruptured. Unfortunately the operators could not identify the cause of the pressure drop. The release of LPG continued for about 5-10 minutes when the gas cloud, estimated at 200 m x 150 m x 2 m high, drifted to a flare stack. It ignited, causing violent ground shock. A number of ground fires occurred. Workers on the plant now tried to deal with the escape taking various action. At a late stage somebody pressed the emergency shut down button.About fifteen minutes after the initial release the first BLEVE occurred. For the next hour and a half there followed a series of BLEVEs as the LPG vessels violently exploded. LPG was said to rain down and surfaces covered in the liquid were set alight. The explosions were recorded on a seismograph at the University of Mexico.
34Contributing Factors Plant layout - the positioning of vessels Emergency isolationSurvivability of critical systemsEmergency plan and site accessFailings in technical measuresThe total destruction of the terminal occurred because there was a failure of the overall basis of safety which included the layout of the plant and emergency isolation featuresPlant Layout: positioning of the vesselsIsolation: emergency isolation meansThe terminal’s fire water system was disabled in the initial blast. Also the water spray systems were inadequate.Active / Passive Fire Protection: survivability of critical systems, insulation thickness, water delugeThe installation of a more effective gas detection and emergency isolation system could have averted the incident. The plant had no gas detection system and therefore when the emergency isolation was initiated it was probably too late.Leak / Gas Detection: gas detectionHindering the arrival of the emergency services was the traffic chaos, which built up as local residents sought to escape the area.Emergency Response / Spill Control: site emergency plan, access of emergency vehicles
35Guidance values for safe separation distances For prevention of Domino EffectsThermal radiation from fire (Jet/ Flash/ Pool/ Fireball)12.5 kW/m2 1% Fatality level4.5 kW/m2 Safe for firefightersOverpressure from Explosion (UVCE/ VCE/ BLEVE)0.1 bar 1% Fatality level
37Plants/Flammable storages should be sited in the open air Site Factors to be considered where Risks of release of flammable/ toxic materials existsPlants/Flammable storages should be sited in the open airLocating all high-volume storage of flammable / toxic material well outside process areas;Hazardous area classification (HAC) to designate areas for elimination of ignition sources .Locating hazardous plant away from main roadways through the site;Fitting remote-actuated isolation valves where high inventories of hazardous materials may be released into vulnerable areas;Provision of ditches, dykes, embankments, sloping terrain to contain and control releases & limit safety & environmental effects;in the open air so that minor leaks or thermal outbreathing can be dissipated by natural ventilation.Maintenance procedures should include the displacement of vapours from hazardous areas before work beginsBuildings should be designed so that all parts of the building are well ventilated by natural or forced ventilation.
38Incident at POL Depot, Jaipur, 29th Oct 2009, 6:10 pm Liquid Motor Spirit had gushed out, when the tank was being lined up (made ready for pumping to BPCL) because MOV connecting to the tank was also open when the Hammer Blind was in the changeover positionProduct leaked for 75 minutes tons of MS= 20 tons TNT before explosion tookAfter explosion, fire occurred in 9 of the 11 tanks and the fire continued till the fuel contents were totally burnt.60000KL product burned out in 11 day11 fatalities, many injured and 280 cr loss3 Operators and 1 shift officer present at siteThe accident was the non-observance of normal safe procedure involving sequence of valve operation in the line up activity and an engineering design which permitted use of a “Hammer Blind Valve”.Hammer Blind Valve is a device which is used for positively isolating a pipeline. The design of the Hammer Blind valve allows a large area at the top of the valve (at the valve bonnet) to be completely open every time the when valve position needed to be changed.It was through this open area that the liquid MS had gushed out, when the tank was being lined up (made ready for pumping to BPCL) because MOV connecting to the tank was also open when the Hammer Blind was in the changeover positionProduct leaked for 75 minutes tons of MS= 20 tons TNT before explosion tookAfter explosion, fire occurred in 9 of the 11 tanks and the fire continued till the fuel contents were totally burnt. Two MS tanks which did not ignite immediately caught fire after a few hours. These two tanks experienced seal fire and their roof was not blown60000KL product burned out in 11 day11 fatalities, many injured and 280 cr lossLoss of primary containmentLoss of secondary containmentInadequate mitigation measuresShortcomings in design and engineering specificationsDefunct Vital emergency shutdown systemAbsence of Operating Personnel in Vital areaAbsence of On-site and Off-site Emergency MeasuresUNCONTROLLED LOSS OF PRIMARY CONTAINMENT IN THE FORM OF A JET OF GASOLINEWrong Operation of valves by operatorImproper Equipment (Hammer Blind valve)Absence of Second OperatorLack of supervisionOperating personnel incapacitated
39LOSS OF SECONDARY CONTAINMENT Open condition of dyke valve in tank dykedrainage system is connected to storm water drain also which is open to atmosphere, Hydrocarbon entering this allows vapor to spread throughout installation.INADEQUATE MITIGATION MEASURESMOV closure from control room was malfunctionNon availability of SCBANo emergency plan for the scenarioNo emergency responderSHORTCOMINGS IN DESIGN AND ENGINEERING SPECIFICATIONSSelected device (HBV) for positive isolation is potentially hazardous ( open to atmosphere while in operation)Operating area was inside dyke for MOV and HBVOperating area access/escape unsatisfactoryMOV was used for tank isolation as well as for Hammer Blind isolation. No fall back provisionPush buttons of MOV’s too close to each otherLocations of push buttons difficult to see while standing in front of MOVApproachability of valves poor, very congestedFire water, fire pumps & storage tanks – water adequacy norms not based on major fire explosion. Location of five pumps and FW storage not idealBleed valve between HOV and MOV not provided even though on P&IDSecond escape route from installation near pipeline area was blocked by a wall which had been constructed to close the gateRestricted VHF communication facility, paging facility for operating staff and no Public Address System
40Critical factors to be considered in plant layout Location of control room /ProtectionFire water tank and fire water pump houseCongestion in the plant site because of buildings, structures, pipelines, trees etc.The emergency exit gate shall be away from the main gate and always be available for use for personnel evacuation during emergency.Evacuation routes should not be blocked by poor plant layoutExtract from IOC Fire Accident Report 10.5 Plant LayoutThe control room should be located far away from potential leak sources as far as practical. Otherwise, the control room should be made blast proof.Fire water tank and fire water pump house should be located far away from potential leak sources/tankage area.Locate buildings and structures in the upwind direction (for the majority of the year) as far as practicable.Avoid congestion in the plant site because of buildings, structures, pipelines, trees etc. The location of these individual facilities should be decided based on Quantitative Risk Assessment.All buildings which are not related to terminal operation shall be located outside the plant area. This includes the canteen also where any spark or open flame may exist.Wherever the tank terminal site also have pipeline division operational area in the same site, the control rooms for both the tank terminal and pipeline shall be located in the same operational building.The emergency exit gate shall be away from the main gate and always be available for use for personnel evacuation during emergency.
42Positioning of occupied buildings The distance between occupied buildings and plant buildings( w.r.t dangers of explosion, fire and toxicity).Locate buildings and structures in the upwind directionCongestion in the plant site because of buildings, structures, pipelines, trees etc.All buildings which are not related to terminal operation shall be located outside the plant area. (eg. canteen, ignition sources)Personnel with more general site responsibilities should usually be housed in buildings sited in a non-hazard area near the main entrance.In all cases occupied buildings should not be sited downwind of hazardous plant areas.
43HPCL-Vizag refinery explosion 14th September 1997 Fire broke out at 6:15 am, following a suspected leak in the LPG pipeline from the Vizag port to the storage farm.It caused a series of explosions, and soon spread to at least six other naphtha and petrol tanks.
44Damages ( HPCL Refinery Fire ) Affected the entire product terminal area, including 11 storage tanks containing naptha, petrol, diesel, kerosene and furnace oil, besides the six ''Horton spheres'' containing LPG.The refinery's administrative building, its canteen and some other buildings came crashing down like a pack of cardsEven an earthquake measuring eight on the Richter scale would not have caused so much damage.
45What to do in case of Restricted Space- Case study of Fire at IOC filling station (petrol bunk) Gas tanker filling underground tanks of the LPG outlet suddenly caught fire, Caused by leakage of LPG from a nozzle of a gas tanker3 persons were killed and a dozen others injuredThe fire engulfed a gas tanker, an electricity transformer and three cars and spread to a nearby multi-storey apartment building.Ignition followed by Fire - spread to nearby houses and burnt trees and damaged electricity poles and wires.Estimate about 12 to 15 tonnes of fuel went up in flames with the fire raging for six hours
46IOC LPG Explosion Jaipur - Oct 12 ,2008 Entire gas station was engulfed in flamesExplosion took place in the tanker itself, destroying it completely. , the impact of which was felt in the entire Shastri Nagar residential area up to a distance of three kilometresAfter 15 minutes of the gas that had leaked , the tanker blew off.The rear shell of the tanker had been thrown 250 feet and made a big hole into an buildingtanker exploded at that time and huge flames that were thrown out of it 350 feet awayForensic officials suspect that after refueling, starting of the tanker by Saleem and Meena might have led to the explosion.eyewitness accounts that some welding work was undergoing within the pump premises due to which leaked gas caught fireseeing the flames coming out of the pump.tanker exploded at that time and huge flames that were thrown out of it350 feet awayFirst, the gas that had leaked caused small flames of fire. After 15 minutes, the tanker blew off.The rear shell of the tanker had been thrown 250 feet and made a big hole into an underconstruction buildingInitially the company's own employees were deployed for the shifting of gas from the tankers to the pumping stations . But gradually with the number of pumps supplying LPG going up, the company adopted a policy of outsourcing
47Risk Analysis Need to Be Applied Helps inForecasting any unwanted situationEstimating damage potential of such situationDecision making to assess the suitability of sitesEvaluating effectiveness of control measures
49Risk The probability of suffering a harm or loss. A combination of hazard and ProbabilityRisk = Probability of occurrence of hazard X magnitude of hazardMeasurement of RiskIndividual RiskSocietal Risk
51ALARP – As Low As Reasonable Practicable Tolerable only if risk reductionIs impracticable or cost isgrossly disproportionate tothe improvement gained
52Summary & ConclusionPoorly laid out site increases risk of an accident especially in MAH group of IndustriesSite layout factors should be considered during Plant Layout design phaseRisk and Damage contours (based on consequence Analysis) helps to demarcate hazardous areasRisk analysis may be required to decide the project when there is restriction of space.Risk levels criteria as stipulated in IS should be employed to decide the case