15 Incident Investigation 15.1. Overview /5.7.7. Introduction An incident is an unplanned event with the potential for undesirable consequences. This definition is meant to include both accidents, and situations in which there were near misses. Thus, the definition covers all cases where there was, or could have been: injury; loss of, or damage to, property; or the release of hazardous or toxic material to the environment. Organizations typically investigate incidents to determine their causes and to seek ways of preventing their recurrence. The process of incident investigation generally utilizes a team-based approach involving: gathering and analyzing the evidence; drawing conclusions as to the causes of the incident; generating corrective or preventive actions; and summarizing, documenting, and disseminat- ing the findings. Proper documentation of incident investigation results provides the basis for corrective actions leading to improvements in the organization's process safety management (PSM) program and, accordingly, should enhance plant safety. This chapter discusses PSM documentation requirements for incident investigation. A description of many of the available methods of incident investigation techniques and how they can be applied is given in the CCPS book, Guidelines for Investigating Chemical Process Incidents. 75.7.2. Goals and Benefits The goal of an incident investigation is to define the facts related to the event, determine the causes, and develop remedial actions to control or eliminate recurrence. Each of these steps should be properly documented. An effective incident reporting and investigation program has many benefits, including:
Transcript
15
Incident Investigation
15.1. Overview
/5.7.7. Introduction
An incident is an unplanned event with the potential for undesirable consequences.This definition is meant to include both accidents, and situations in which therewere near misses. Thus, the definition covers all cases where there was, or couldhave been: injury; loss of, or damage to, property; or the release of hazardous ortoxic material to the environment.
Organizations typically investigate incidents to determine their causes and toseek ways of preventing their recurrence. The process of incident investigationgenerally utilizes a team-based approach involving: gathering and analyzing theevidence; drawing conclusions as to the causes of the incident; generatingcorrective or preventive actions; and summarizing, documenting, and disseminat-ing the findings. Proper documentation of incident investigation results providesthe basis for corrective actions leading to improvements in the organization'sprocess safety management (PSM) program and, accordingly, should enhanceplant safety. This chapter discusses PSM documentation requirements for incidentinvestigation.
A description of many of the available methods of incident investigationtechniques and how they can be applied is given in the CCPS book, Guidelines forInvestigating Chemical Process Incidents.
75.7.2. Goals and Benefits
The goal of an incident investigation is to define the facts related to the event,determine the causes, and develop remedial actions to control or eliminaterecurrence. Each of these steps should be properly documented.
An effective incident reporting and investigation program has many benefits,including:
• assurance that incidents will be reported and investigated;• confidence that the underlying or root causes of incidents have been
discovered;• identification of appropriate corrective actions for management review and
implementation;• development of improved knowledge, techniques, and facilities that should
reduce recurrence of similar incidents;• enhancement of process safety within the affected facility;• heightened awareness of operational safety requirements fostered by the
dissemination of reports and recommendations;• identification of needed PSM program improvements by analysis of lessons
learned,-,• compliance with applicable regulatory requirements;• development of detailed, credible information for litigation support; and• reduction in downtime and operating costs by control of accidental losses.
15.2. Description of Incident Investigation
/5.2.7. Objectives
The primary objective of an incident investigation is to determine and documentthe root causes and contributing causes of an incident. Recommendations andcorrective action plans are then developed with the intent of preventing suchincidents in the future.
/5.2.2. Conducting Incident Investigations
Incidents cannot be investigated if they are not reported. To ensure reporting, anincident should be viewed as any event that is unusual or out of the ordinary,whether or not harm resulted from its occurrence. The initial reporting of suchevents should not be limited to those perceived to be serious or potentially seriousincidents, since the seriousness of an event often cannot be determined withoutanalysis. It is important that all incidents be reported so that corrective action canbe established before a similar occurrence results in a serious accident. Therefore,barriers to incident reporting (e.g., fear of management reprisal) must be removedto promote timely reporting by employees at any level of the organization.
The investigation of an incident involves four stages of activity: gatheringevidence, analyzing the evidence, drawing conclusions, and formulating recom-mendations. Each of these stages are discussed further below.
Gathering Evidence. Investigation of an incident should commence as soon aspossible since the quality and quantity of evidence begin to decline immediatelyafter the incident. This is the case with the memories of witnesses and can also be
true for certain types of physical evidence. For maximum effectiveness, an incidentinvestigation should start within 48 hours; this is a requirement for processescovered by current regulatory requirements.
Evidence gathering activities include:
• interviewing witnesses;• taking photographs (or making video tapes) of the incident scene;• identifying and securing physical evidence (e.g., pieces of a damaged
vessel);• collecting paper or computer records (e.g., procedures, instrument charts,
log books); and• sampling key process streams and arranging for analysis.
Although the gathering of evidence should begin as soon as possible, com-pletion of this task may require a significant interval of time; e.g., if time-consum-ing laboratory analyses are required.
Analyzing the Evidence. The typical incident investigation will amass a significantamount of evidence, only a portion of which will be pertinent to explaining theincident. It is often helpful to arrange this data based on a chronological sequence,attempting to establish a time line for the events leading up to, and perhapsfollowing, the incident. This allows the identification of conflicting and supportingevidence, and may point to information gaps that require additional evidence.
Drawing Conclusions. The goal of an incident investigation is to identify the rootcauses of the event. The identification of root causes is not always obvious andsometimes requires special analytical techniques. Selection of the method of analysisdepends on the unique circumstances of the case at hand; a description of many ofthe methods of incident analysis techniques and how they can be applied is given inthe CCPS book, Guidelines for Investigating Chemical Process Incidents.
Formulating Recommendations. Once the investigation team has analyzed theevidence from the incident investigation and agreed upon the probable causes,recommendations for corrective or remedial actions should be formulated. Gen-erally, recommendations fall into one of two classes:
• those for correcting the specific identified problems (causes) involved inthe incident; and
• those for correcting systemic problems (causes) identified during theinvestigation.
At least one recommendation for corrective action should be developed foreach causal finding reported. In evaluating recommendations, the incident inves-tigation team should consider the following:
• evaluation of the safety of the relevant operation;• identification of objectives and priorities for the corrective action;
• limiting criteria (i.e., limits of performance and/or cost and collateralimpacts);
• practical alternatives to correct the deficiency;• testing of possible alternative recommendations against the objectives,
limiting criteria and evaluation of possible adverse effects; and• implementation procedures, controls, responsibilities, and feedback com-
munication.
There are other benefits that may be derived from incident investigations, inaddition to achieving the immediate goal of preventing the recurrence of aparticular incident. These are discussed below.
Improved Operational Safety. Documentation of incident investigations pro-vides a historical record that can be used to search for similarities in past events.Use of such records can lead to improvements in future designs and operationalprocedures and can help to identify trends more clearly. Appropriate categoriesor classifications of incident information can be established in the documentationso that accident analysis can focus on possible links. Examples of categories forclassifying incident data may include:
• root cause;• contributing (multiple) causes;• related PSM elements (e.g., process knowledge, training, process equip-
Improved PSMPrqgram. The incident investigation program may identify areasfor potential improvement in either the overall PSM program, or in individualPSM elements. These areas of improvement should be documented. Someexamples are:
• updating of purging requirements as a result of an explosion attributed toresidual volatile organics in a vessel prepared for maintenance (OperatingProcedures);
• necessity for retraining of plant operators based on the revised operatinginstructions (Training); and
• increasing the frequency of periodic maintenance on critical safety equip-ment (Process Equipment Integrity).
Satisfaction of Legal Requirements. The procedures and documentation in-volved in incident investigation must satisfy applicable federal, state, and localregulatory requirements. Insurers may also have specific requirements that shouldbe incorporated into the procedures.
15.3. Incident Investigation Documentation
75.3.7. Incident Investigation Program Documentation
An organization implementing an incident investigation program should establisha documented program defining the goals and requirements of incident investi-gation and providing detailed procedures outlining how incident investigationswill be performed. Such preplanning is an important part of a well designedincident investigation program and should be clearly documented. The programdocumentation should also clearly establish responsibilities and accountability forthe incident investigation element.
The program documentation would typically address the following:
basic statement of policy;which types of incidents are to be investigated;the importance of promptly initiating the investigation;who is to initiate an investigation;who is to lead the investigation;responsibilities of the leader, who will:—determine the scope of team activities;—call and preside over team meetings;—establish the time table and assign tasks;—ensure that all pertinent data has been collected;—advise management as to the progress of the investigation;—bring the investigation process to a timely conclusion; and—issue a timely report to management.team selection;objectives of the investigation;selection of the investigation method(s) to be used;documentation requirements for incident investigation;resolution of all recommendations;any special policies regarding incidents that may be subject to litigation;interactions with regulatory authorities;records control, storage and issue, retention; andauditing of incident reports.
The program documentation should also address requirements and proce-dures for communicating the conclusions of the investigation to management andto affected employees and contractors.
15.3.2. Documentation of Incident Investigation Results
Incident investigations are typically documented via a formal summary reportcontaining the following information:
• a summary of the incident;• a statement of who performed the investigation and when it was conducted;• a discussion, where pertinent, of the incident analysis technique used;• an analysis of the evidence, citing pertinent events leading up to the
incident and identifying its causes, including root causes;• recommendations proposed to prevent a repeat of the incident; and• a summary of supporting data.
Some organizations use a standardized form for the incident investigationreport. An example of one such form is provided in Figure 15-1 (pages 260-263).
The supporting data for an investigation report can be quite voluminous, andmay include the following:
• documents received, examined, analyzed or consulted during the investi-gation (the actual documents may be included, or they may be referenced);transcripts or audio tapes of interviews;visual evidence (e.g., photographs, video, etc.);maps or sketches of the incident scene;calculations;inventories of physical evidence, indicating storage location; andphysical and/or chemical analysis or test reports.
Appendixes can be very helpful in organizing this supporting data. Anappendix index and/or table of contents would be advisable, in addition to crossreferencing in the main body of the report. Alternatively, some organizations maychose to document the more voluminous portions of this information, not inappendixes to the report, but as a separate report with limited distribution.
Regulatory requirements may dictate that report findings be communicatedto affected personnel. If this is the case, confirmation of such communicationsshould also be documented.
15.3.3. Resolution of Incident Report Recommendations
Follow-up is one of the most important aspects of incident investigation. Unlesscauses are identified and ways to prevent recurrence are implemented, repetitionof the incident remains possible. Resolution of recommendations is, therefore,vital to achieve PSM program goals. The following documentation practices forrecommendations should be followed:
• each recommended action should be clearly and unambiguously stated inthe investigation report (including the intent underlying the recommen-dation);
• the report should identify:—the person responsible implementing the resolution; and—a target date for implementation, or for presenting a report on the
recommendation to the responsible manager.
• the final resolution of each recommendation should be documentedshowing that either:—the recommendation has been implemented as proposed;—an equivalent alternative has been adopted; or—upon further consideration, the recommendation has been deemed to
be impractical or unnecessary. In this case, the rationale for the decisionshould also be documented.
The documentation of resolution of recommendations may be included inthe original incident investigation report, in an addendum to the report, or in aseparate follow up report.
15.4. Records Management
In addition to the description of the incident investigation program given inSection 15.3.1, the organization's PSM documentation should define pertinentrecords management practices. Some records management considerations arediscussed in this section. The reader may also wish to refer to Chapter 4, RecordsManagement, for more general guidance.
15.4.1. Responsibilities and Accountability
The responsibility for collection, storage, and management of incident investiga-tion records should be clearly defined. A member of the safety organization,because of routine involvement in the investigation program, might be anappropriate choice.
75.4.2. Records Control
Records media will likely vary. Frequently, the evidence examined during aninvestigation will consists of paper documents (including logbooks, logsheets, andinstrument recorder charts), photographs, magnetic tape, etc. In a broader sense,however, the concept of incident investigation records should be expanded toinclude physical evidence such as hardware and pieces of equipment. All of thesevarious types of records must be controlled in accordance with the organization'srecords management procedures. These procedures should address not only theneeds of the organization, but also applicable legal, regulatory, and insurancerequirements.
As pointed out in the CCPS book, Guidelines for Investigating Chemical ProcessIncidents., the potential for litigation associated with incidents may dictate uniquerecords control practices. For example, records associated with pending litigationmay require a chain-of-custody record. Organizations may wish to enlist theassistance of legal counsel when promulgating incident investigation recordscontrol practices, particularly with regard to retention and purge schedules.
Accident/Incident Investigation Form
Chemical or substance involved:
Amount discharged to air:
Amount discharged to land:
Amount discharged to sewer:
Describe injury/property loss:
Estimated cost of property loss:
Why did it happen?
Estimated remedial cost:
Exposure above LH. Limit Value:
CERCLA or SARA reportable quantity exceeded?
Agencies notified:
Disposition of material:
How did incident occur?
Job Title
Site
Name
Plant
Last First Initial
Incident Location
Supervisor
Incident Date Date Reported Division Code
Incident Time
OccupationalNon-occupational
UndeterminedPrecautionary
8. Overexposure9. Illness
10. Spill11. Release12. Property Loss13. Permit Excursion14. Off-Site15. Other
Classification:D 1. First Aid DD 2. Medical DD 3. Restricted Duty DD 4. Days Away D
From Work DD 5. Near Miss DD 6. Fire DD 7. Contractor DComplete Reverse Side.
FIGURE 15-1. Typical Accident/Incident Investigation Form (Sheet 1 of 2)
Investigator/Employee
Safety & Loss Prevention
Ecology
Rev 3/92
Corrective action(s) to prevent recurrence:,
Immediate corrective action(s):
Responsibility Target Date
Date
Date
Date
Date Supervisor
Date Department Head
Date Plant/Site Manager
InstructionsComplete all sections on the front page. The Accident/Incident investigation Reportis not complete untitthe appropriate signatures are obtained.Copies of all injury and illness investigations, except first aids, must be sent toCorporate Safety ^nd Loss Prevention and environmental incident investigationslnis investigation is "open" until corrective action has been completed.The following is for the purpose of maintaining computerized Statistics. Completeeach block A" through "V" using the appropriate code number assigned for eachentry from the data below.When applicable, complete the below section for number of restricted days and/ornumber of days away from work
Industrial lniuries CodeEmployee Soc. Sec. No.
SIC Code Time in that jobDivision Accident typeSite Accident agencyPlant Nature of
^e Body part affectedSex Primary causeHours Worked Contrib causeOvertime Contrib. causeEmployee Status Contrjb causeOccupation Unsafe act/conditionTime Employed
Number of restricted days: Final DEst. DNumber of days away from work: Final DEst. D
A. Employee Social Security NumberB. SIC codeC. Division
O. Accident agency/involved equipment01 -Fired vessels-boiler, incin., etc.02-Reactors, columns.vessels, etc. >15 psig03-Process eqpt. tanks, bins <15 psig04-Gas or liquid handling (into)05-Soyds handling (into)06-Mechanical power transmission-gears, couplings, belts, pultevs07-Portable eqpt. machinery08-Hoists, cranes, etc.09-Over-the-road automobiles, and trucks, incl. tank trucks10-lndustrial trucks, forklifts. end loaders, tractors. -bicycles11 -Railroad, rolling stock, incl. tank cars12-Piping. hoses, valves and fittings13-Containers-drums. boxes, pails, cylinders etc.14-Ladders. scaffold,15-Floors. working/walking surfaces16-Tools-hand (wrenches, etc.)17-Knives. scissors18-Tools-powered (elec.. air. etc.)19-Electrical distrib. sys./apparatus20-Office equipment21 -Laboratory equipment22-Fabrication. assembly or machine shop equipment23-Chemicals24-Hot liquids/gas88-Other99-Unknown
P. Nature of injury/illness01 -Amputation, avulsion 21 -Skin disease or disorder02-Fracture. dislocate, crush 22-Dust disease of the lung03-Cut, scrape, puncture, sting bite 23-Respiratory-toxic agents04-Bruise, contusion 24-Poisoning-chronic05-lrritation 25-Physical agents-radiation, etc.06-Herma. rupture 26-Repeated trauma-noise, etc07-Sprain, strain 29-Other illness^eart cont., etc08-Burn-chemica! 00-No injury09-Burn-thermal or electrical10-Heat stress, exhaustion, sunstroke,11 -Suffocate, drown, asphyxiate(lack of oxygen)12-Concussion. unconscious13-Poisoning-acute14-Other
50-Body Systems51 -Circulatory52-Respiratory53-Neurological54-Reproductive00-No body partinjured
R.-U. Causal factors (primary and contributory causes)Supervision10-lncorrect/incomplete procedures, instructions11-Rules, procedures, work methods not enforced12-lnadequate training of employee(s)13-Proper tools, equipment not provided14-Deficient storage/material handling practices15-lnadequate housekeeping, area inspections16-Too much rush on job by supervisorEmployee20-Physical limitation21-Deficient in skill or ability22-lnfluence of drugs or alcohol23-Lack of alertness30-Failure to follow written procedures or rule31-Confined space entry procedure32-Hot work procedure33-Line breaking procedure34-Lockout/tagout procedure35-Mamtenance. adjustment or cleaning on moving/pressurized equipment/line40-Failure to follow oral instructions50-Failure to use personal protective equipment51-Operating without authority52-Takmg an unsafe position53-Unsafe speed, haste, short cut54-lmproper use of tool, equipment, material55-Use of incorrect tool/equipment/matenal56-lmproper manual material handling
Equipment Environment60-Defective equipment, tool material 70-Horseplay/distraction by fellow employee61-lnadequate or missing guards 71-Error by fellow employee62-lnadequate or bypassed safety 72-Unsafe eqpt./matl's./actions of 3rd party
L. Time employed, years01-less than 1 04-10-2002-1 to 5 05->2003-5 to 10
M. Time in that job. years01-less than 1 04-10 to 2002-1 to 5 05->2003-5 to 10
N. Accident type01-FaII from elevation02-FaII, same level03-Slip or trip without fall04-Struck against object05-Struck by object06-Caught in, under, between07-Overexertion, strain08-Public or contracted transportation09-Motor vehicle (employee's or company's)10-Drowning. buried11-Explosion, implosionContact by.12-Chemicals13-Electncity14-Temperature extremes15-Noise16-Radiation17-Other physical agents18-Animal. insect, plant88-Other
FIGURE 15-1. Typical Accident/Incident Investigation Form (Sheet 2 of 2)
15.5. Auditing
The PSM program documentation should establish auditing requirements for theincident investigation element. The first step in auditing the element is to verifythat a documented program, such as described in Section 15.3.1, exists forimplementing incident investigation.
The second step is to verify that the results of implementing the incidentinvestigation element have been documented in the manner described by theprogram. Particular emphasis should be placed on the documentation of theresolution of recommendations. It should be possible to trace the disposition ofeach recommendation made in the incident investigation reports.
Deficiencies identified during the audit must be documented and resolved ina timely manner. Further details on auditing procedures and methods can be foundin Chapter 14, Auditing and the CCPS book, Guidelines for Auditing Process SafetyManagement Systems.
15.6. Examples
This section gives examples that illustrate the importance of thorough incidentinvestigation, documentation, and adequate follow-up of recommendations, toensure that incidents do not recur. For additional examples see What Went Wrong?Case Histories of Process Plant Disasters^ Second Edition, by Trevor Kletz.
15.6.1. Inadequate Follow-Up to Incident Investigation Causes Fire
A change was made in the operating practices for taking a reactor off-line forcatalyst change, because a small fire had occurred during a prior catalyst change.The change was recorded in the log book and in a handwritten note at the plant,but apparently was not formally documented nor followed-up after investigationof the incident. The note was eventually lost and an operator resumed using theoriginal operating procedures, contained in the standard operating proceduresmanual. Another fire occurred.
Appropriate documentation of the results of the incident investigation andrecommended actions and a subsequent audit of recommendation follow-up couldhave prevented the second fire.
A refinery experienced significant, costly damage to the internals of a heavy gas/oilfractionator on numerous occasions during start-up operations. Damage wasthought to be from water (condensate) left in the system after steaming, whichflashed upon contact with the hot oil introduced during the dry out/warm upperiod. These incidents and conditions were extensively investigated and docu-
mented. It was eventually determined that circulation for not less than 18 hoursat an oil temperature not exceeding 2750F was needed to safely and completelydry out the accumulated condensate in the lower portion of the fractionator andits associated piping. This recommendation was documented within the incidentinvestigation report.
Facility personnel incorporated the appropriate instructions into the start-upprocedure for the fractionator. The revised procedure prevented flashing anddamage to vessel internals, and avoided costs previously incurred for downtimeand repairs.
15.7. References
AIChE-CCPS5 ^idelines for Auditing Process Safety Management Systems, 1993.AIChE-CCPS, Guidelines for Investigating Chemical Process Accidents, 1992.Kletz, T. A., Lessons from Disaster: How Organizations Have No Memory and Accidents Recur,
Institution of Chemical Engineers, UK, 1993.Kletz, T.A., What Went Wrong? Case Histories of Process Plant Disasters, Gulf Publishing
Co., Houston, 1985.Lees, F.P., Loss Prevention in the Process Industries, Butterworth, London, England, 1986.Sanders, Roy, E., Managementof* Change in Chemical Plants: Learning from Case Histories,
Butterworth, London, England, 1993.Occupational Safety and Health Administration, Process Safety Management of Highly
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