Qualitative & Quantitative Hazard Analysis

Qualitative & QuantitativeHazard AnalysisGuidelines for Chemical Process QuantitativeRisk Analysis, CCPS / AIChEGuidelines for Hazard Evaluation Procedure,CCPS / AIChE

Risk Analysis Methodology1. HazardIdentificationProcessSafetyAnalysis3. FrequencyQuantificationData banksHAZOP5. RiskReductionFTAChecklistSMSLOPAMitigationIndex tion2. antificationRiskPerception6. Risk Assessment

Qualitative vs &EI, EA : Failure Modes and Effects Analysis, F&EI : Dow Fire and Explosion IndexCEI : Dow Chemical Exposure Index, HRA : Human Reliability Analysis

IntroductionSuccessful hazard evaluation study can bedefined as one in whichThe need for risk information has been metThe results are of high quality and are easy fordecision makers to useThe study has been performed with the minimumresources needed to get job done

Hazard EvaluationFactors influencing the selection of hazardevaluation techniqueMotivation for the studyType of result neededType of information available to perform the studyCharacteristics of the analysis problemPerceived risk associated with the subject processor activityResource available and analyst/managementpreference

AFMEAWhat DesignCommissioning

Safety ReviewPurposeKeeps operating personnel alert to the process hazardsReview operating procedures for necessary revisionsSeek to identify equipment or process changes that couldhave introduces new hazardEvaluate the design basis of control and safety systemTypes of resultQualitative descriptions of potential safety problem andsuggested corrective actionsResource requirementsP&ID, flowcharts, plant procedures for start-up, shutdown,maintenance and emergencies, hazardous incident reports,process material characteristics

OverviewDetailed inspection to identify hazardous processdesign characteristics, plant conditions,operating practice or maintenance activitiesConduct periodic inspection of an operating planthelps ensure that implemented risk managementprogram meet original expectations andstandardsAddress all plant equipment. Instrumentation,associated utilities, environmental protectionfacility, maintenance areas and service

Preparing for the reviewDefine which systems, procedures, operationsand personnel will be evaluatedFollowing task should be completedAssemble a detailed description of the plantReview the known hazards and process history with thereview team membersReview all of the applicable codes, standards andcompany requirementSchedule interviews with specific individual responsiblefor safe process operationRequest available records concerning personnelinjuries, accident/incident reports, equipmentinspection, pressure relief valve testing, safety/healthaudits etc.

Performing the reviewObtain and review copies of plant drawing as wellas operating, maintenance and emergencyproceduresSome question that might be addresses areIs there a system for keeping important processdocumentation and drawing up-to-date?Is the equipment in good condition?Are the pressure relief or other safety property installed,well maintained and properly identified?Do plant records show the history of inspecting/testingof the equipment and the safety devices?Are safe practice followed and permits used?

Checklist AnalysisPurposeEnsure that organizations are complying withstandard practicesType of resultsList of questions based on deficiencies ordifferenceCompleted checklist contains “yes”, “no”, “notapplicable” or “need more information” answerto the questionResource requirementEngineering design procedure, operatingpractices manualExperiences manager or engineer withknowledge of process

OverviewExperience –based approachUse s list of specific items to identify knowntypes of hazards, design deficiencies andpotential accident situationCan be used to evaluate materials, equipment orprocessEnsure that a piece of equipment conforms withaccepted standards and it may also identifyareas that required further evaluation

Analysis procedureSelecting or developing an appropriate checklistAppropriate checklist from available informationAnalyst must use his own experience and theinformation available from authoritative reference togenerate an appropriate checklistPerforming the reviewInclude tours and visual inspections of the subjectprocess areas by the HE team membersReviewer respond to the checklist issues based onobservations from site visits, system documentation,interviews with operating personnel and personnelperceptionDocumenting the resultsSummarize the deficiencies noted during the tours ormeeting and any specific recommendation

Relative RankingPurposeDetermine the process areas or operation that arethe most significant with respect to the hazard ofconcern in a given studyTypes of resultAn ordered list of process equipment, operationor activitiesResource requirementsBasic physical and chemical data on thesubstance used in the process or activity

OverviewRank process areas or plant operations bycomparing the hazards attributes of chemicalsDistinguish between several process areas basedon the magnitude of hazards, likelihood ofaccidents and/or severity of potential accidentsCan address fire, explosion and/or toxicityhazards and associated safety, health,environmental and economic effects for aprocess or activity

Relative ranking techniques may be usedduring any phase of a plant or processlifetime to:Identify the individual process areas thatcontribute most to the anticipated overall hazardand accident attributes of a facilityIdentify the key material properties, processconditions and/or process characteristics thatcontribute most to the anticipated hazards andaccident of a single area or an entire facilityCompare to anticipate hazard and accidentattributes of process areas or facilities to otherwhose attributes are better understood

Considering factor for implementing the relativeranking indexMaterial propertiesProcess conditionsProcess characteristics and support systemsPurging, ventilation, cooling, heating etcSystem design and constructionFire proofing, equipment layout, corrosion resistance etcOperational activitiesOperator training, written procedures etc.PSM activitiesInspection and testing intervals, maintenance activities etc.Exposure possibilitiesOperation time and frequency, number of operator activitiesetc.

Summary of relative ranking indexes-1Dow Fire and Explosion Index(F&EI)Rankings of process units can be usedTo direct specific safety improvement efforts relating toimportant parameters used in the F&EI calculationTo identify areas for more detailed hazard evaluation or riskanalysis studyMond IndexExtension of the Dow F&EIIncludes factors that address the toxicity hazardsassociated with materials in process unitsSubstance Hazard Index(SHI)Way of ranking material hazards defined as “equilibriumvapor concentration(EVC) of a material at 20C divided byan acute toxicity concentration”

Summary of relative ranking indexes-2Chemical Exposure Index(CEI)Addresses five types of factors that can influence theeffects of release of the materialAcute toxicityVolatile portion of material which could be releasedDistance to areas of concernMolecular weight of the substanceVarious process parameters such as temperature,pressure, reactivity and so forth

Analysis ProcedurePreparing for the reviewInformation for preparing the analysisSite planLists of materials, chemical properties and quantitiesGeneral process diagram and equipment layout drawingDesign and operating dataTechnical guides for the selected ranking techniquePerforming the reviewFollow the instruction in the technical guide for thattechnique to perform the evaluationThe calculates risk index should be summarized tofacilitate comparisons among the areaDocument the results

Presentation ContentParticipationIntroduction with an overview and backgroundLiterature reviewDefinition of the problemObjectiveIdentification of important issuesAnalysis of the problemDescription of fundamentalsRelation to engineering principlesGuidelines for applying the information or experience inengineering situationsPatterns that help determine process safety strategiesInclude applicable government regulations.Conclusions and recommendations

Dow Fire and Explosion Index(F&EI) Rankings of process units can be used To direct specific safety improvement efforts relating to important parameters used in the F&EI calculation To identify areas for more detailed hazard evaluation or risk analysis study Mond Index Extension of the Dow F&EI Includes factors that address the toxicity hazards