This edition first published 2019
© 2019 the American Institute of Chemical Engineers

A Joint Publication of the American Institute of Chemical Engineers and John Wiley & Sons, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions.

The rights of CCPS to be identified as the author of the editorial material in this work have been asserted in accordance with law.

Registered Office
John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA

Editorial Office
111 River Street, Hoboken, NJ 07030, USA

For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com.

Wiley also publishes its books in a variety of electronic formats and by print-on-demand. Some content that appears in standard print versions of this book may not be available in other formats.

Limit of Liability/Disclaimer of Warranty

While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

Library of Congress Cataloging-in-Publication Data is available.

Hardback ISBN: 9781119529071

Cover Images: Silhouette, oil refinery © manyx31/iStockphoto; Stainless steel © Creativ Studio Heinemann/Getty Images, Inc.; Dow Chemical Operations, Stade, Germany/Courtesy of The Dow Chemical Company

It is sincerely hoped that the information presented in this document will lead to an even more impressive safety record for the entire industry. However, the American Institute of Chemical Engineers, its consultants, the CCPS Technical Steering Committee and Subcommittee members, their employers, their employers’ officers and directors, and Baker Engineering and Risk Consultants, Inc.^®, and its employees do not warrant or represent, expressly or by implication, the correctness or accuracy of the content of the information presented in this document. As between (1) American Institute of Chemical Engineers, its consultants, CCPS Technical Steering Committee and Subcommittee members, their employers, their employers’ officers and directors, and Baker Engineering and Risk Consultants, Inc.^®, and its employees and (2) the user of this document, the user accepts any legal liability or responsibility whatsoever for the consequences of its use or misuse.

Figure 2.1 Event Tree for a Process-related Incident

Figure 2.2 Swiss Cheese Model

Figure 2.3 Latent (hidden) Failure

Figure 2.4 Incident Prevention Strategies

Figure 2.5 Universal Concept for Controlling Risk

Figure 3.1 Overview of Investigation Tools

Figure 3.2 Schematic of an MES display

Figure 3.3 Top Portion of the Generic MORT Tree

Figure 3.4 Common Features of Investigation Methodologies

Figure 4.1 Management System for Process Safety Investigation

Figure 4.2 Checklist for Developing an Incident Investigation Plan

Figure 5.1 Logic Tree for Determining Incident Classification

Figure 5.2 Example Risk Matrix for Determining Incident Classification

Figure 6.1 Investigation Team Collaboration

Figure 7.1 Iteration between Witness and Physical Evidence Collection and Analysis

Figure 7.2 List of Potential Witnesses

Figure 7.3 Illustration of Human Observation Limitations

Figure 7.4 Overview of Interview Process

Figure 8.1 Iteration between Data Analysis and Data Gathering

Figure 8.2 Forms of Data Fragility

Figure 8.3 As-found Position of Valves—Example Photo

Figure 8.4 Initial Site Visit—Example Photo

Figure 8.5 Timeline Example Based on Precise Data

Figure 8.6 Timeline Example Based on Approximate Data

Figure 8.7 Timeline Example Based on a Combination of Precise and Approximate Data

Figure 8.8 Timeline Tips

Figure 8.9 Sequence Diagram for Tank Overflow Example

Figure 9.1 Scientific Method Process

Figure 9.2 Basic Steps in Failure Analysis

Figure 9.3 Rules for Causal Factor Charting

Figure 9.4 Example of a Causal Factor Chart

Figure 10.1 Example of 5 Whys Root Cause Analysis

Figure 10.2 Example of Ishikawa Fishbone Diagram

Figure 10.3 Structured Root Cause Methods Described in This Chapter

Figure 10.4 Flowchart for Root Cause Determination Using Logic Trees

Figure 10.5 Generic Logic Tree Displaying the AND-Gate

Figure 10.6 Generic Logic Tree for a Fire

Figure 10.7 Generic Logic Tree Displaying the OR-Gate

Figure 10.8 Logic Tree using the OR-Gate to establish an Ignition Source

Figure 10.9 Other Symbols Used in Logic Trees

Figure 10.10 Logic Tree Tips

Figure 10.11 Example Top of the Logic Tree, Employee Slip

Figure 10.12 Example Logic Tree Branch Level, Oil Spill

Figure 10.13 Example Logic Tree, Hand-carried Containers

Figure 10.14 Logic Tree, Slip/Trip/Fall Incident

Figure 10.15 Logic Tree Top, Employee Burn

Figure 10.16 Logic Tree Branch, Acid Spray

Figure 10.17 Expanded Logic Tree Sample, Employee Burn

Figure 10.18 Operator Fatality Branch

Figure 10.19 Fire Branch

Figure 10.20 Fact/Hypothesis Matrix for the Kettle Exit Piping Failure

Figure 10.21 Exit Piping Crack Branch

Figure 10.22 Flowchart for Root Cause Determination—Predefined Tree/Checklist

Figure 10.23 Example of Root Causes Arranged Hierarchically within a Section of a Predefined Tree

Figure 10.24 Incident Sequence

Figure 10.25 Complete Causal Factor Chart for Fish Kill Incident

Figure 10.26 Top of the Predefined Tree

Figure 10.27 First Question of the Human Performance Difficulty Category

Figure 10.28 Human Engineering Branch of the Tree

Figure 10.29 Analysis of the Human Engineering Branch

Figure 11.1 Common Human Factors Model

Figure 11.2 Example of Poor Pump and Switch Arrangement

Figure 11.3 Incident Causation Model

Figure 12.1 Incident Investigation Recommendation Flowchart

Figure 12.2 Layers of Safety

Figure 12.3 Bow-Tie Barrier Method

Figure 12.4 Example Recommendations and Assessment Strategies

Figure 14.1 Flowchart for Implementation and Follow-up

Figure 16.1 Example Safety Alert

Figure 16.2 CCPS Process Safety Beacon

Figure 16.3 ICI Safety Newsletter No. 96/1 & 2

Figure 16.4 ICI Safety Newsletter No. 96/7

Figure 16.5 Learning Event Report Example

Figure 16.6 Process Safety Bulletin Example

Table 2.1 Attributes of a Management System

Table 3.1 Some Characteristics of Selected Public Methodologies

Table 4.1 Suggested Training for Effective Implementation

Table 5.1 Common Classification Schemes

Table 5.2 Tier 1 Process Safety Event Severity Categories

Table 5.3 Example of Likelihood Levels for Determining Incident Classification

Table 5.4 Examples of the Impacts of a 1000-lb Cyclohexane Release

Table 7.1 Example Questions for Witnesses and Emergency Responders

Table 8.1 Scene Activities and Typical Responsibilities

Table 8.2 Examples of Paper Evidence

Table 8.3 Examples of Electronic Data

Table 8.4 Examples of Position Data

Table 8.5 Example Data Collection Form for Recording Physical Evidence

Table 9.1 Example Fact/Hypothesis Matrix – Chemical Reduction Explosion

Table 10.1 Strengths and Weaknesses of the 5 Whys Technique

Table 10.2 Strengths and Weaknesses of Logic Trees

Table 10.3 Strengths and Weaknesses of Predefined Trees

Table 11.1 Human Factors Issues

Table 13.1 Sample Sections of an Incident Investigation Report

Table 13.2 Findings, Causal Factors, Root Causes and Recommendations

Table 13.3 Example Checklist for Written Reports

Table 15.1 Requirement Compliance Checklist

Table 15.2 Investigation Key Element Audit Checklist

Table 15.3 Example Categories for Incident Investigation Findings

Table 15.4 Recommendations Review Checklist

Table 15.5 Example Follow-Up Checklist

Table 16.1 Questions for Identifying Learning Opportunities

The American Institute of Chemical Engineers (AIChE) has helped chemical plants, petrochemical plants, and refineries address the issues of process safety and loss control for over 30 years. Through its ties with process designers, plant constructors, facility operators, safety professionals, and academia, the AIChE has enhanced communication and fostered improvement in the high safety standards of the industry. AIChE’s publications and symposia have become an information resource for the chemical engineering profession on the causes of incidents and the means of prevention.

The Center for Chemical Process Safety (CCPS), a directorate of AIChE, was established in 1985 to develop and disseminate technical information for use in the prevention of major chemical accidents. CCPS is supported by a diverse group of industrial sponsors in the chemical process industry and related industries who provide the necessary funding and professional guidance for its projects. The CCPS Technical Steering Committee and the technical subcommittees oversee individual projects selected by the CCPS. Professional representatives from sponsoring companies staff the subcommittees and a member of the CCPS staff coordinates their activities.

Since its founding, CCPS has published many volumes in its “Guidelines” series and in smaller “Concept” texts. Although most CCPS books are written for engineers in plant design and operations and address scientific techniques and engineering practices, several guidelines cover subjects related to chemical process safety management. A successful process safety program relies upon committed managers at all levels of a company, who view process safety as an integral part of overall business management and act accordingly.

Incident investigation is an essential element of every process safety management program. This book presents underlying principles, management system considerations, investigation tools, and specific methodologies for investigating incidents in a way that will support implementation of a rigorous process safety program at any facility. The principles and suggested practices contained in this expanded third edition are not limited to chemical and petroleum process incidents. The basic concepts and provided examples are equally applicable to mining, pharmaceutical, manufacturing, mail order fulfillment, and numerous other hazardous industries.

A team of incident investigation experts from the petroleum, chemical, and consulting industries, as well as a regulatory agency representative, drafted the chapters for this guideline and provided real-world examples to illustrate some of the tools and methods used in their profession. The subcommittee members reviewed the content extensively and industry peers evaluated this book to help ensure it represents a factual accounting of industry best practices. This third edition of the guideline provides updated information on many facets of the investigative process as well as additional details on important considerations such as human factors, forensics, and legalities surrounding incident investigations.

The American Institute of Chemical Engineers wishes to thank the Center for Chemical Process Safety (CCPS) and those involved in its operation, including its many sponsors whose funding made this project possible; the members of its Technical Steering Committee who conceived of and supported this Guidelines project; and the members of its Incident Investigation Subcommittee. The Incident Investigation Subcommittee of the Center for Chemical Process Safety authored this third edition of the Guidelines for Investigating Process Safety Incidents.

The members of the CCPS Incident Investigation Subcommittee were:

Michael Broadribb, Baker Engineering and Risk Consultants, Inc.

Laurie Brown, Eastman Chemical Company

Chonai Cheung, Contra Costa County

Eddie Dalton, BASF

Carolina Del Din, PSRG

Jerry Forest, Celanese, Subcommittee Chair

Scott Guinn, Chevron Corporation

Christopher Headen, Cargill

Kathleen Kas, Dow Chemical Company

Mark Paradies, System Improvements, Inc.

Nestor Paraliticci, Andeavor

Muddassir Penkar, Evonik Canada Inc.

Morgan Reed, Exponent

Meg Reese, Occidental Chemical Corp.

Marc Rothschild, DuPont

Joy Shah, Reliance Industries Ltd

Dan Sliva, CCPS Staff Advisor

Robert (Bob) Stankovich, Eli Lilly

Lee Vanden Heuvel, ABS Consulting

Terry Waldrop, AIG

Scott Wallace, Olin

Della Wong, Canadian Natural Resources

The third edition was authored by Baker Engineering and Risk Consultants, Inc. The authors at BakerRisk were:

Quentin A. Baker

Michael P. Broadribb

Cheryl A. Grounds

Thomas V. Rodante

Roger C. Stokes

Dan Sliva was the CCPS staff liaison and was responsible for overall administration of the project.

CCPS also gratefully acknowledges the comments and suggestions received from the following peer reviewers:

Amy Breathat, NOVA Chemicals Corporation

Steven D. Emerson, Emerson Analysis

Patrick Fortune, Suncor Energy

Walter L. Frank, Frank Risk Solutions, Inc.

Barry Guillory, Louisiana State University

Jerry L. Jones, CFEISBC Global

Gerald A. King, Armstrong Teasdale LLP

Susan M. Lee, Andeavor

William (Bill) D. Mosier, Syngenta Crop Protection, LLC

Mike Munsil, PSRG

Pamela Nelson, Solvay Group

Katherine Pearson, BP Americas

S. Gill Sigmon, AdvanSix

Their insights, comments, and suggestions helped ensure a balanced perspective to this Guideline.

The efforts of the document editor at BakerRisk are gratefully acknowledged for contributions in editing, layout, and assembly of the book. The document editor was Phyllis Whiteaker.

The members of the CCPS Incident Investigation Subcommittee wish to thank their employers for allowing them to participate in this project and lastly, we wish to thank Anil Gokhale of the CCPS staff for his support and guidance.