GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

This book is one in a series of process safety guideline and concept books published by the Center for Chemical Process Safety (CCPS) Please go to www wileycomgoccps for a full list of titles in this series

This book is one in a series of process safety guideline and concept books published by the Center for Chemical Process Safety (CCPS) Please go to www wileycomgoccps for a full list of titles in this series

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Center for Chemical Process Safety New York NY

Center for Chemical Process Safety

WILEY A JOHN WILEY amp SONS INC PUBLICATION

Copyright copy 2012 by American Institute of Chemical Engineers Inc

Published by John Wiley amp Sons Inc Hoboken New Jersey All rights reserved Published simultaneously in Canada

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 scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representation or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print however may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data

American Institute of Chemical Engineers Center for Chemical Process Safety Guidelines for evaluating process plant buildings for external explosions fires and toxic releases mdash

2nd ed p cm

Rev ed of Guidelines for evaluating process plant buildings for external explosions and fires copy 1996

Includes index ISBN 978-0-470-64367-9 (hardback) 1 Chemical plantsmdashFires and fire prevention 2 Explosions 3 Chemical plantsmdashRisk assessment

4 Hazardous wastes I Guidelines for evaluating process plant buildings for external explosions and fires II Title

TH9445C47A46 2012 6602804mdashdc23 2011049805

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

Copyright copy 2012 by American Institute of Chemical Engineers Inc

Published by John Wiley amp Sons Inc Hoboken New Jersey All rights reserved Published simultaneously in Canada

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 scanning or otherwise except as permitted under Section 107 or 108 of the 1976 United States Copyright Act without either the prior written permission of the Publisher or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center Inc 222 Rosewood Drive Danvers MA 01923 (978) 750-8400 fax (978) 750-4470 or on the web at wwwcopyrightcom Requests to the Publisher for permission should be addressed to the Permissions Department John Wiley amp Sons Inc 111 River Street Hoboken NJ 07030 (201) 748-6011 fax (201) 748-6008 or online at httpwwwwileycomgopermission

Limit of LiabilityDisclaimer of Warranty While the publisher and author have used their best efforts in preparing this book they make no representation or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages including but not limited to special incidental consequential or other damages

For general information on our other products and services please contact our Customer Care Department within the United States at (800) 762-2974 outside the United States at (317) 572-3993 or fax (317) 572-4002

Wiley also publishes its books in a variety of electronic formats Some content that appears in print however may not be available in electronic formats For more information about Wiley products visit our web site at wwwwileycom

Library of Congress Cataloging-in-Publication Data

American Institute of Chemical Engineers Center for Chemical Process Safety Guidelines for evaluating process plant buildings for external explosions fires and toxic releases mdash

2nd ed p cm

Rev ed of Guidelines for evaluating process plant buildings for external explosions and fires copy 1996

Includes index ISBN 978-0-470-64367-9 (hardback) 1 Chemical plantsmdashFires and fire prevention 2 Explosions 3 Chemical plantsmdashRisk assessment

4 Hazardous wastes I Guidelines for evaluating process plant buildings for external explosions and fires II Title

TH9445C47A46 2012 6602804mdashdc23 2011049805

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

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

v

CONTENTS

List of Figures xiii List of Tables xvii Acknowledgements xix Glossary xxi

1 INTRODUCTION 1

11 Objective 4 12 Building Siting Evaluation Process 5 13 Selection of Approach 6 14 Background 6

141 Flixborough UK Vapor Cloud Explosion in Chemical Plant 8

15 Phillips Pasadena Texas USA Propylene HDPE Unit VCE and BLEVEs 10 151 BP Texas City Texas USA Discharge from Atmospheric

Vent Resulting in a VCE 13 152 Hickson amp Welch Ltd Castleford UK Jet Fire 15

16 Evolution of Design and Siting Practices for Buildings in Process Plants 18 161 Brief History of Building Designs 18 162 Standards for Building and Equipment Siting and Separation 19 163 Standards and Criteria for Building Design and the Need 19

for Site-Specific Evaluation 17 Organization of the Book 20

2 MANAGEMENT OVERVIEW 21

21 Process Overview 21 211 Explosion Fire and Toxic Release Phenomena 21 212 Statement of the Problem 25 213 Analysis Approach Selection 25 214 Steps in the Process 26

22 Management Responsibilities under API RP-752 and API RP-753 27 221 Meeting Expectations - Managements Role in the Process 27 222 Maintaining the Process 28

VII

VIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

3 DETERMINING THE SCOPE OF THE BUILDING SITING 31 EVALUATION

31 Introduction 31 32 Buildings Considered 31

321 Buildings Intended for Occupancy 31 322 Buildings That May be Excluded from the Siting Study 33 323 Buildings Evaluated on a Case-by-Case Basis 36

33 Scenario Selection 36 331 Consequence-based Scenario Selection 38 332 Risk-based Scenario Selection 40 333 Explosion Scenarios 41 334 Fire Scenarios 42 335 Toxic Scenarios 44

4 BUILDING SITING EVALUATION CRITERIA 45

41 Introduction 45 42 Occupant Vulnerability 46 43 Criteria for Existing Buildings Exposed to Explosion Hazards 48

431 Building Exposure Criteria for Explosion 48 432 Building Consequence (Damage) Criteria 48

44 Criteria for Fires 58 441 Spacing Table Approach 58 442 Building Exposure Criteria for Fire 58 443 Fire Criteria Based on Occupant Vulnerability 60 444 Smoke 61

45 Criteria for Toxic Exposures 62 451 Criteria Based on Presence of a Toxic Cloud 62 452 Toxic Criteria Based on Occupant Exposure 63

46 Criteria for Building Upgrades and New Buildings 64 47 Risk Criteria 65

471 Use of Individual Risk Measures 65 472 Use of Societal and Aggregate Risk Measures 67

5 EXPLOSION HAZARDS 71

51 Introduction 71 52 Select Explosion Approach 72

521 Evaluation of Existing Buildings 73 522 Siting and Design of New Buildings 74

53 Modeling and Quantifying and Explosion Hazards 74 531 Vapor Cloud Explosions (VCEs) 74 532 Pressure Vessel Burst 76 533 Boiling Liquid Expanding Vapor Explosions (BLEVEs) 77 534 Condensed Phase Explosions 77

54 Building Response to Explosion Hazards 78

CONTENTS ιχ

541 General 78 542 Building Damage Levels (BDLs) 79 543 Component Damage Levels 80 544 Detailed Analysis 82 545 Identifying Limiting Factors 89

55 Occupant Vulnerability to Explosion Hazards 90 56 Actions Required at the Completion of the Evaluation 90

561 Results That Meet Criteria 90 562 Results That Do Not Meet Criteria 91

6 FIRE HAZARDS ASSESSMENT 93

61 Introduction 93 611 Overview of Fire Phenomena and Sources of Information 93 612 Overview of Assessment of Fires in a Building Siting 95

Evaluation 62 Determining if a Fire Hazard Exists 97 63 Spacing Table Approach 97 64 Performing a Consequence-Based or Risk-Based Building Siting

Evaluation for Fire 99 641 Modeling and Quantifying Fire Hazards 101 642 Building Response to Fire Hazards 102 643 Calculation of Internal Temperature Risk 103

65 Occupant Response to Fire Hazards 105 651 Relevance of Training and Drills - Human Reactions 106

66 Defining the Fire Protection Concept 106 661 Evacuation Considerations 106 662 Impact to Operations 108

7 TOXIC HAZARDS ASSESSMENT 109

71 Introduction 109 72 Determining If a Toxic Hazard Exists 109 73 Building Siting Evaluation for Toxics 111

731 Modeling and Quantifying Toxic Hazards 113 732 Building Design for Occupant Protection from Toxics 117

74 Defining the Toxic Protection Concept 120 741 Strategy for Building Design and Occupancy 120 742 Selection of Strategy to Implement 120

75 Evacuation vs Sheltering-In-Place 120 751 Attributes of Shelter-in-Place Strategy 120 752 Attributes of Evacuation Strategy 122 753 Strategy for Leak Detection 122

8 FREQUENCY AND PROBABILITY ASSESSMENT 125

81 Introduction 82 Developing a Scenario List

125 127

X GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

821 Individual Source Based Approach 127 822 Scenario Outcome Based Approach 128

83 Calculation of Frequency of Initiating Event or Accident 129 831 Use of Company Historical Data 129 832 Use of Historical Industry (Generic) Data 130 833 Prediction by Quantifying Contributing Causes 133 834 Factors that May Indicate Failure Rates Different than

Standard Values 138 835 Data Modification Methods 140 836 Risk-Based Inspection 143 837 Elimination of Failure Classes 143 838 Interference Between Frequency Modification Methods 144

84 Probability and Frequency of Final Outcomes 144 841 Event Trees 144 842 Quantification of an Event Tree 145

85 Unit-Based Outcome Frequencies 149

9 RISK ASSESSMENT 151

91 Introduction 151 911 Scope of Risk in This Book 151 912 Definition of Risk in This Book 152 913 Qualitative Versus Quantitative Risk Assessment 153

92 Risk Measure Types 154 921 Common Risk Measures 154 922 Alternative Risk Types 156 923 Summary of Risk Types 157

93 Calculating Risk 158 931 Overview 158 932 Calculating Individual Risk 159 933 Calculating Aggregate Risk 161

94 Interpretation and Use of Risk Measures 169

10 MITIGATION PLANS AND ONGOING RISK MANAGEMENT 171

101 Development of Mitigation Plans 171 1011 Selection of Mitigation Measures 171 1012 Mitigation Schedule 175 1013 Interim Measures 176

102 Building Modifications 177 1021 Structural Strengthening to Increase Protection from

Explosion Hazards 177 1022 Structural Modifications to Mitigate Fire Hazards 181 1023 Structural Modifications to Mitigate Toxic Hazards 181

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

CONTENTS

List of Figures xiii List of Tables xvii Acknowledgements xix Glossary xxi

1 INTRODUCTION 1

11 Objective 4 12 Building Siting Evaluation Process 5 13 Selection of Approach 6 14 Background 6

141 Flixborough UK Vapor Cloud Explosion in Chemical Plant 8

15 Phillips Pasadena Texas USA Propylene HDPE Unit VCE and BLEVEs 10 151 BP Texas City Texas USA Discharge from Atmospheric

Vent Resulting in a VCE 13 152 Hickson amp Welch Ltd Castleford UK Jet Fire 15

16 Evolution of Design and Siting Practices for Buildings in Process Plants 18 161 Brief History of Building Designs 18 162 Standards for Building and Equipment Siting and Separation 19 163 Standards and Criteria for Building Design and the Need 19

for Site-Specific Evaluation 17 Organization of the Book 20

2 MANAGEMENT OVERVIEW 21

21 Process Overview 21 211 Explosion Fire and Toxic Release Phenomena 21 212 Statement of the Problem 25 213 Analysis Approach Selection 25 214 Steps in the Process 26

22 Management Responsibilities under API RP-752 and API RP-753 27 221 Meeting Expectations - Managements Role in the Process 27 222 Maintaining the Process 28

VII

VIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

3 DETERMINING THE SCOPE OF THE BUILDING SITING 31 EVALUATION

31 Introduction 31 32 Buildings Considered 31

321 Buildings Intended for Occupancy 31 322 Buildings That May be Excluded from the Siting Study 33 323 Buildings Evaluated on a Case-by-Case Basis 36

33 Scenario Selection 36 331 Consequence-based Scenario Selection 38 332 Risk-based Scenario Selection 40 333 Explosion Scenarios 41 334 Fire Scenarios 42 335 Toxic Scenarios 44

4 BUILDING SITING EVALUATION CRITERIA 45

41 Introduction 45 42 Occupant Vulnerability 46 43 Criteria for Existing Buildings Exposed to Explosion Hazards 48

431 Building Exposure Criteria for Explosion 48 432 Building Consequence (Damage) Criteria 48

44 Criteria for Fires 58 441 Spacing Table Approach 58 442 Building Exposure Criteria for Fire 58 443 Fire Criteria Based on Occupant Vulnerability 60 444 Smoke 61

45 Criteria for Toxic Exposures 62 451 Criteria Based on Presence of a Toxic Cloud 62 452 Toxic Criteria Based on Occupant Exposure 63

46 Criteria for Building Upgrades and New Buildings 64 47 Risk Criteria 65

471 Use of Individual Risk Measures 65 472 Use of Societal and Aggregate Risk Measures 67

5 EXPLOSION HAZARDS 71

51 Introduction 71 52 Select Explosion Approach 72

521 Evaluation of Existing Buildings 73 522 Siting and Design of New Buildings 74

53 Modeling and Quantifying and Explosion Hazards 74 531 Vapor Cloud Explosions (VCEs) 74 532 Pressure Vessel Burst 76 533 Boiling Liquid Expanding Vapor Explosions (BLEVEs) 77 534 Condensed Phase Explosions 77

54 Building Response to Explosion Hazards 78

CONTENTS ιχ

541 General 78 542 Building Damage Levels (BDLs) 79 543 Component Damage Levels 80 544 Detailed Analysis 82 545 Identifying Limiting Factors 89

55 Occupant Vulnerability to Explosion Hazards 90 56 Actions Required at the Completion of the Evaluation 90

561 Results That Meet Criteria 90 562 Results That Do Not Meet Criteria 91

6 FIRE HAZARDS ASSESSMENT 93

61 Introduction 93 611 Overview of Fire Phenomena and Sources of Information 93 612 Overview of Assessment of Fires in a Building Siting 95

Evaluation 62 Determining if a Fire Hazard Exists 97 63 Spacing Table Approach 97 64 Performing a Consequence-Based or Risk-Based Building Siting

Evaluation for Fire 99 641 Modeling and Quantifying Fire Hazards 101 642 Building Response to Fire Hazards 102 643 Calculation of Internal Temperature Risk 103

65 Occupant Response to Fire Hazards 105 651 Relevance of Training and Drills - Human Reactions 106

66 Defining the Fire Protection Concept 106 661 Evacuation Considerations 106 662 Impact to Operations 108

7 TOXIC HAZARDS ASSESSMENT 109

71 Introduction 109 72 Determining If a Toxic Hazard Exists 109 73 Building Siting Evaluation for Toxics 111

731 Modeling and Quantifying Toxic Hazards 113 732 Building Design for Occupant Protection from Toxics 117

74 Defining the Toxic Protection Concept 120 741 Strategy for Building Design and Occupancy 120 742 Selection of Strategy to Implement 120

75 Evacuation vs Sheltering-In-Place 120 751 Attributes of Shelter-in-Place Strategy 120 752 Attributes of Evacuation Strategy 122 753 Strategy for Leak Detection 122

8 FREQUENCY AND PROBABILITY ASSESSMENT 125

81 Introduction 82 Developing a Scenario List

125 127

X GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

821 Individual Source Based Approach 127 822 Scenario Outcome Based Approach 128

83 Calculation of Frequency of Initiating Event or Accident 129 831 Use of Company Historical Data 129 832 Use of Historical Industry (Generic) Data 130 833 Prediction by Quantifying Contributing Causes 133 834 Factors that May Indicate Failure Rates Different than

Standard Values 138 835 Data Modification Methods 140 836 Risk-Based Inspection 143 837 Elimination of Failure Classes 143 838 Interference Between Frequency Modification Methods 144

84 Probability and Frequency of Final Outcomes 144 841 Event Trees 144 842 Quantification of an Event Tree 145

85 Unit-Based Outcome Frequencies 149

9 RISK ASSESSMENT 151

91 Introduction 151 911 Scope of Risk in This Book 151 912 Definition of Risk in This Book 152 913 Qualitative Versus Quantitative Risk Assessment 153

92 Risk Measure Types 154 921 Common Risk Measures 154 922 Alternative Risk Types 156 923 Summary of Risk Types 157

93 Calculating Risk 158 931 Overview 158 932 Calculating Individual Risk 159 933 Calculating Aggregate Risk 161

94 Interpretation and Use of Risk Measures 169

10 MITIGATION PLANS AND ONGOING RISK MANAGEMENT 171

101 Development of Mitigation Plans 171 1011 Selection of Mitigation Measures 171 1012 Mitigation Schedule 175 1013 Interim Measures 176

102 Building Modifications 177 1021 Structural Strengthening to Increase Protection from

Explosion Hazards 177 1022 Structural Modifications to Mitigate Fire Hazards 181 1023 Structural Modifications to Mitigate Toxic Hazards 181

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

VIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

3 DETERMINING THE SCOPE OF THE BUILDING SITING 31 EVALUATION

31 Introduction 31 32 Buildings Considered 31

321 Buildings Intended for Occupancy 31 322 Buildings That May be Excluded from the Siting Study 33 323 Buildings Evaluated on a Case-by-Case Basis 36

33 Scenario Selection 36 331 Consequence-based Scenario Selection 38 332 Risk-based Scenario Selection 40 333 Explosion Scenarios 41 334 Fire Scenarios 42 335 Toxic Scenarios 44

4 BUILDING SITING EVALUATION CRITERIA 45

41 Introduction 45 42 Occupant Vulnerability 46 43 Criteria for Existing Buildings Exposed to Explosion Hazards 48

431 Building Exposure Criteria for Explosion 48 432 Building Consequence (Damage) Criteria 48

44 Criteria for Fires 58 441 Spacing Table Approach 58 442 Building Exposure Criteria for Fire 58 443 Fire Criteria Based on Occupant Vulnerability 60 444 Smoke 61

45 Criteria for Toxic Exposures 62 451 Criteria Based on Presence of a Toxic Cloud 62 452 Toxic Criteria Based on Occupant Exposure 63

46 Criteria for Building Upgrades and New Buildings 64 47 Risk Criteria 65

471 Use of Individual Risk Measures 65 472 Use of Societal and Aggregate Risk Measures 67

5 EXPLOSION HAZARDS 71

51 Introduction 71 52 Select Explosion Approach 72

521 Evaluation of Existing Buildings 73 522 Siting and Design of New Buildings 74

53 Modeling and Quantifying and Explosion Hazards 74 531 Vapor Cloud Explosions (VCEs) 74 532 Pressure Vessel Burst 76 533 Boiling Liquid Expanding Vapor Explosions (BLEVEs) 77 534 Condensed Phase Explosions 77

54 Building Response to Explosion Hazards 78

CONTENTS ιχ

541 General 78 542 Building Damage Levels (BDLs) 79 543 Component Damage Levels 80 544 Detailed Analysis 82 545 Identifying Limiting Factors 89

55 Occupant Vulnerability to Explosion Hazards 90 56 Actions Required at the Completion of the Evaluation 90

561 Results That Meet Criteria 90 562 Results That Do Not Meet Criteria 91

6 FIRE HAZARDS ASSESSMENT 93

61 Introduction 93 611 Overview of Fire Phenomena and Sources of Information 93 612 Overview of Assessment of Fires in a Building Siting 95

Evaluation 62 Determining if a Fire Hazard Exists 97 63 Spacing Table Approach 97 64 Performing a Consequence-Based or Risk-Based Building Siting

Evaluation for Fire 99 641 Modeling and Quantifying Fire Hazards 101 642 Building Response to Fire Hazards 102 643 Calculation of Internal Temperature Risk 103

65 Occupant Response to Fire Hazards 105 651 Relevance of Training and Drills - Human Reactions 106

66 Defining the Fire Protection Concept 106 661 Evacuation Considerations 106 662 Impact to Operations 108

7 TOXIC HAZARDS ASSESSMENT 109

71 Introduction 109 72 Determining If a Toxic Hazard Exists 109 73 Building Siting Evaluation for Toxics 111

731 Modeling and Quantifying Toxic Hazards 113 732 Building Design for Occupant Protection from Toxics 117

74 Defining the Toxic Protection Concept 120 741 Strategy for Building Design and Occupancy 120 742 Selection of Strategy to Implement 120

75 Evacuation vs Sheltering-In-Place 120 751 Attributes of Shelter-in-Place Strategy 120 752 Attributes of Evacuation Strategy 122 753 Strategy for Leak Detection 122

8 FREQUENCY AND PROBABILITY ASSESSMENT 125

81 Introduction 82 Developing a Scenario List

125 127

X GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

821 Individual Source Based Approach 127 822 Scenario Outcome Based Approach 128

83 Calculation of Frequency of Initiating Event or Accident 129 831 Use of Company Historical Data 129 832 Use of Historical Industry (Generic) Data 130 833 Prediction by Quantifying Contributing Causes 133 834 Factors that May Indicate Failure Rates Different than

Standard Values 138 835 Data Modification Methods 140 836 Risk-Based Inspection 143 837 Elimination of Failure Classes 143 838 Interference Between Frequency Modification Methods 144

84 Probability and Frequency of Final Outcomes 144 841 Event Trees 144 842 Quantification of an Event Tree 145

85 Unit-Based Outcome Frequencies 149

9 RISK ASSESSMENT 151

91 Introduction 151 911 Scope of Risk in This Book 151 912 Definition of Risk in This Book 152 913 Qualitative Versus Quantitative Risk Assessment 153

92 Risk Measure Types 154 921 Common Risk Measures 154 922 Alternative Risk Types 156 923 Summary of Risk Types 157

93 Calculating Risk 158 931 Overview 158 932 Calculating Individual Risk 159 933 Calculating Aggregate Risk 161

94 Interpretation and Use of Risk Measures 169

10 MITIGATION PLANS AND ONGOING RISK MANAGEMENT 171

101 Development of Mitigation Plans 171 1011 Selection of Mitigation Measures 171 1012 Mitigation Schedule 175 1013 Interim Measures 176

102 Building Modifications 177 1021 Structural Strengthening to Increase Protection from

Explosion Hazards 177 1022 Structural Modifications to Mitigate Fire Hazards 181 1023 Structural Modifications to Mitigate Toxic Hazards 181

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

CONTENTS ιχ

541 General 78 542 Building Damage Levels (BDLs) 79 543 Component Damage Levels 80 544 Detailed Analysis 82 545 Identifying Limiting Factors 89

55 Occupant Vulnerability to Explosion Hazards 90 56 Actions Required at the Completion of the Evaluation 90

561 Results That Meet Criteria 90 562 Results That Do Not Meet Criteria 91

6 FIRE HAZARDS ASSESSMENT 93

61 Introduction 93 611 Overview of Fire Phenomena and Sources of Information 93 612 Overview of Assessment of Fires in a Building Siting 95

Evaluation 62 Determining if a Fire Hazard Exists 97 63 Spacing Table Approach 97 64 Performing a Consequence-Based or Risk-Based Building Siting

Evaluation for Fire 99 641 Modeling and Quantifying Fire Hazards 101 642 Building Response to Fire Hazards 102 643 Calculation of Internal Temperature Risk 103

65 Occupant Response to Fire Hazards 105 651 Relevance of Training and Drills - Human Reactions 106

66 Defining the Fire Protection Concept 106 661 Evacuation Considerations 106 662 Impact to Operations 108

7 TOXIC HAZARDS ASSESSMENT 109

71 Introduction 109 72 Determining If a Toxic Hazard Exists 109 73 Building Siting Evaluation for Toxics 111

731 Modeling and Quantifying Toxic Hazards 113 732 Building Design for Occupant Protection from Toxics 117

74 Defining the Toxic Protection Concept 120 741 Strategy for Building Design and Occupancy 120 742 Selection of Strategy to Implement 120

75 Evacuation vs Sheltering-In-Place 120 751 Attributes of Shelter-in-Place Strategy 120 752 Attributes of Evacuation Strategy 122 753 Strategy for Leak Detection 122

8 FREQUENCY AND PROBABILITY ASSESSMENT 125

81 Introduction 82 Developing a Scenario List

125 127

X GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

821 Individual Source Based Approach 127 822 Scenario Outcome Based Approach 128

83 Calculation of Frequency of Initiating Event or Accident 129 831 Use of Company Historical Data 129 832 Use of Historical Industry (Generic) Data 130 833 Prediction by Quantifying Contributing Causes 133 834 Factors that May Indicate Failure Rates Different than

Standard Values 138 835 Data Modification Methods 140 836 Risk-Based Inspection 143 837 Elimination of Failure Classes 143 838 Interference Between Frequency Modification Methods 144

84 Probability and Frequency of Final Outcomes 144 841 Event Trees 144 842 Quantification of an Event Tree 145

85 Unit-Based Outcome Frequencies 149

9 RISK ASSESSMENT 151

91 Introduction 151 911 Scope of Risk in This Book 151 912 Definition of Risk in This Book 152 913 Qualitative Versus Quantitative Risk Assessment 153

92 Risk Measure Types 154 921 Common Risk Measures 154 922 Alternative Risk Types 156 923 Summary of Risk Types 157

93 Calculating Risk 158 931 Overview 158 932 Calculating Individual Risk 159 933 Calculating Aggregate Risk 161

94 Interpretation and Use of Risk Measures 169

10 MITIGATION PLANS AND ONGOING RISK MANAGEMENT 171

101 Development of Mitigation Plans 171 1011 Selection of Mitigation Measures 171 1012 Mitigation Schedule 175 1013 Interim Measures 176

102 Building Modifications 177 1021 Structural Strengthening to Increase Protection from

Explosion Hazards 177 1022 Structural Modifications to Mitigate Fire Hazards 181 1023 Structural Modifications to Mitigate Toxic Hazards 181

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

X GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

821 Individual Source Based Approach 127 822 Scenario Outcome Based Approach 128

83 Calculation of Frequency of Initiating Event or Accident 129 831 Use of Company Historical Data 129 832 Use of Historical Industry (Generic) Data 130 833 Prediction by Quantifying Contributing Causes 133 834 Factors that May Indicate Failure Rates Different than

Standard Values 138 835 Data Modification Methods 140 836 Risk-Based Inspection 143 837 Elimination of Failure Classes 143 838 Interference Between Frequency Modification Methods 144

84 Probability and Frequency of Final Outcomes 144 841 Event Trees 144 842 Quantification of an Event Tree 145

85 Unit-Based Outcome Frequencies 149

9 RISK ASSESSMENT 151

91 Introduction 151 911 Scope of Risk in This Book 151 912 Definition of Risk in This Book 152 913 Qualitative Versus Quantitative Risk Assessment 153

92 Risk Measure Types 154 921 Common Risk Measures 154 922 Alternative Risk Types 156 923 Summary of Risk Types 157

93 Calculating Risk 158 931 Overview 158 932 Calculating Individual Risk 159 933 Calculating Aggregate Risk 161

94 Interpretation and Use of Risk Measures 169

10 MITIGATION PLANS AND ONGOING RISK MANAGEMENT 171

101 Development of Mitigation Plans 171 1011 Selection of Mitigation Measures 171 1012 Mitigation Schedule 175 1013 Interim Measures 176

102 Building Modifications 177 1021 Structural Strengthening to Increase Protection from

Explosion Hazards 177 1022 Structural Modifications to Mitigate Fire Hazards 181 1023 Structural Modifications to Mitigate Toxic Hazards 181

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

CONTENTS χι

11 MANAGING THE BUILDING SITING PROCESS 185

111 Management of Change 185 1111 Managing the Occupancy of the Building 18 5

112 Documentation Requirements 187 1121 Building Siting Procedure 187 1122 Mitigation Plan 188

113 Documentation of Mitigation Systems Criteria and Performance 188 1131 Documentation of Mitigation Actions 18 8

114 Maintaining Documentation EverGreen 189

INDEX 201

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

LIST OF FIGURES

Figure 11 Relationship between API RP-752 and API RP-753 3 Figure 12 Overall Process for a Building Siting Evaluation 5 Figure 13 Flixborough Works Prior to the Explosion 8 Figure 14 Aerial View of Damage to the Flixborough Works 9 Figure 15 Damage to the Office Block and Process Areas at the 10

Flixborough Works Figure 16 Phillips Pasadena Plant Prior to the Incident 11 Figure 17 BLEVE at the Phillips Pasadena Site 12 Figure 18 Phillips Pasadena Process Area Damage 12

(Courtesy of FM Global) Figure 19 Aerial View of the ISOM Unit after the Explosion (CSB 2007) 14 Figure 110 Destroyed Trailers West of the Blowdown Drum (arrow in 15

upper left of the figure) Figure 111 Vessel Involved in the Hickson amp Welch Incident 16 Figure 112 Damage to the Control Building from the Jet Flame at 17

Hickson amp Welch Figure 113 Damage to the Control Room and Impact on the Office Block 17

from the Jet Flame at Hickson amp Welch Figure 21 Potential Outcomes of a Hazardous Material Release (Pitblado 23

1996) Figure 41 Building Damage Curves for a High Bay Metal Structure 49

(-40000 sq ft) (DDESB 2009) Figure 42 Illustration of Discrete State BDL Curves 50 Figure 43 Masonry Building BDL 1 (Photo Courtesy of Explosion 51

Research Cooperative) Figure 44 Pre-Engineered Metal Building BDL 1 (Photo Courtesy of 51

Explosion Research Cooperative) Figure 45 Masonry Building BDL 2 A (Photo Courtesy of Explosion 52

Research Cooperative) Figure 46 Pre-Engineered Metal Building BDL 2A (Photo Courtesy of 52

Explosion Research Cooperative) Figure 47 Masonry Building BDL 2B (Photo Courtesy of Explosion 53

Research Cooperative)

XIII

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

XIV GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Figure 48 Pre-Engineered Metal Building BDL 2B (Photo Courtesy of 53 Explosion Research Cooperative)

Figure 49 Masonry Building BDL 3 (Photo Courtesy of Explosion 54 Research Cooperative)

Figure 410 Pre-Engineered Metal Building BDL 3 (Photo Courtesy of 54 Explosion Research Cooperative)

Figure 411 Presentation of HSE Risk Tolerance Levels (HSE 2001) 65 Figure 412 A Three-tier Framework for Risk Interpretation 66 Figure 413 Regulated Acceptability Criteria for Societal Risk (CCPS 68

2009b) Figure 51 Logic Diagram for Siting Buildings with Regards to Explosion 71

Hazards Figure 52 Equivalent Spring-Mass SDOF System 84 Figure 53 Alternative Resistance Functions 84 Figure 54 TDOF System with Panel Loading Beam 86 Figure 55 TDOF System with Two Beams Loading Girder 87 Figure 56 TDOF System with Beams Loading Girders at Midspan 87 Figure 57 TDOF System with Girts Causing Frame Sway 88 Figure 61 Logic Diagram for Evaluating Buildings for Fire Hazards 96 Figure 71 Logic Flowpath for Evaluating Toxic Risk to Occupied 110

Buildings Figure 72 Indoor and Outdoor Mean Concentration for a Very Leaky 118

Building with 20 Air Changes per Hour During a 66 Minute Outdoor Release Event (Wilson 1996)

Figure 73 Comparison of Linear Dosage for Three Sheltering Policies 119 (Wilson and Zelt 1990)

Figure 81 Fault Tree Example 134 Figure 82 Failure Modes Effects and Criticality Assessment Example 136 Figure 83 LOPA Example 137 Figure 84 Modifying Piping Leak Failure Rates to Account for Aging 140

(Thomas 1981) Figure 85 Typical Variation in Wall Thickness with Pipe Diameter 141

(ASME 2004) Figure 86 Loss Cause in the Petrochemical Industry (percentage of 143

losses) (Marsh 1999) Figure 87 Event Tree for Calculating Loss of Containment Outcome 145

Frequencies Figure 88 Basic Quantified Event Tree Example 148 Figure 91 Example of Aggregate (Societal) Risk (F-N) Curve 155

(CCPS 2000) Figure 92 Calculated F-N Curve from Example 167 Figure 101 Steel Posts Added to Exterior of Masonry Wall 178 Figure 102 Additional Steel Framing Inside of Upgraded Door 179 Figure 103 Steel Framing around Door to Secure to Masonry Wall 179

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

LIST OF FIGURES xv

Figure 104 New Girts and Framing Members in Pre-Engineered Metal 180 Building

Figure 105 New Roof Purlins Installed Between Existing Purlins 180

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

LIST OF TABLES

Table 11 Table 31

Table 41 Table 42

Table 43 Table 44 Table 45

Table 46

Table 47 Table 48 Table 49 Table 410 Table 411 Table 412 Table 51 Table 52 Table 53 Table 54 Table 55 Table 61

Table 62 Table 63 Table 64

Table 65

Table 66 Table 67

Selected Accidents Involving Buildings in Process Plants 6 Examples of Credible and Non-Credible Situations for Building 39 Siting Evaluations Abbreviated Injury Scale (AIS) Severity Levels 47 Typical Industry Building Damage Level Descriptions 50 (Baker 2002) US Army COE Building Damage Levels 55 Comparison of Industry and COE BDLs 55 Assumed Building Construction for Default Buildings 57 (Oswald and Baker 2000) Occupant Vulnerabilities () as a Function of Building Damage 57 Level (Oswald and Baker 2000) Fire Presence Criteria 59 Thermal Dose Criteria 60 Occupant Thermal Vulnerability Criteria 61 Common Siting Criteria Used for Toxic Hazards 63 Toxic Vulnerability Criteria 64 Comparison of Sample Individual Risk Criteria 67 Recent Publications in Blast Resistant Design 78 ASCE and COE Component Damage Definitions 81 Window and Door Damage Levels (USACOE 2006) 82 Examples of Applicable TDOF Systems 86 Examples of Non-Applicable TDOF Systems 88 Typical Spacing Requirements for On-Site Buildings for Fire 98 Consequences in Horizontal Distance (ft) [CCPS 2003a] Sources of Information for Protecting Buildings from Fires 99 Risk-Based vs Consequence-Based Fire Study Inputs 100 Example Building Occupant Vulnerability (OV) from Radiant 104 Heat Levels on Building Exterior from Pool and Jet Fires Example Occupant Vulnerabilities Inside Buildings for 104 Ignition Outside Buildings Recommended Design Total Radiation (from API RP 521) 107 Allowable Thermal Radiation Flux Excluding Solar (from 107 EN 1473)

XVII

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

XVIII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Table 71 Risk-Based vs Consequence-Based Toxic Study Inputs 111 Table 81 Simple Illustration of Factors Used to Determine Explosion 126

Frequencies Table 82 Some Commonly-Used Equipment Failure Rate Databases 131 Table 91 Summary of Some Major Types of Risk Measures 157 Table 92 Calculation of Individual Risk 160 Table 93 Calculation of Aggregate Risk 162 Table 94 Summary of Individual Risk Inputs 164 Table 95 Inputs for Aggregate Risk Calculation 165 Table 96 FN Curve Input Data 166 Table 97 Risk Index (Aggregate Risk) Calculation 168 Table 101 Hierarchy of Mitigation Measures (RP-API 2009) 172 Table 102 Passive Mitigation Measures 173 Table 103 Active Mitigation Measures 174 Table 104 Procedural Mitigation Measures 175 Table 105 Examples of Situations in Which Interim Risk Management 176

Measures May be Necessary Table 111 Examples of Unintentional Risk Increases 186

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

ACKNOWLEDGMENTS

The American Institute of Chemical engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to all members of the Guidelines for Evaluating Process Plant Buildings for External Explosions Fires and Toxic Releases Second Edition project and their CCPS member companies for their generous support and technical contributions in the preparation of this book The AIChE and the CCPS also express their gratitude to the team and project managers from Baker Engineering and Risk Consultants who under the direction of Mr Quentin Baker devoted time and expertise to ensure that this project would meet the needs of industry

XIX

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

XX GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS FOR EXTERNAL EXPLOSIONS FIRES AND TOXIC RELEASES

Second Edition

Wayne Garland Chair Glen A Peters Ralph Hodges Kieran J Glynn Robin Pitblado Phillip N Partridge III Thomas C Scherpa Chris Buchwald Chris Gyasi Larry O Bowler John Alderman

SUBCOMMITTEE MEMBERS

Eastman Chemical Company Air Products and Chemicals Inc Bayer Material Science (Retired) BP Det Norske Veritas (USA) Inc

DuPont ExxonMobil Chemical Company Lanxess Corporation Orange Texas SABIC AON Risk Solutions

CCPS Staff Consultant Adrian L Sepeda

CCPS wishes to acknowledge the many contributions of the Baker Engineering and Risk Consultants team with special recognition for outstanding and innovative contributions to the primary authors Quentin Baker Raymond Bennett and Michael Moosemiller and to the technical contributions of Jatin Shah and John Woodward Thanks also go to Moira Woodhouse for technical editing and pulling all the pieces together in the manuscript and Joanna Sobotker for administrative support throughout the project

Before publication all CCPS books are subjected to a thorough peer review process CCPS gratefully acknowledges the time and expertise these peer reviewers put into their reviews and acknowledges the thoughtful comments and suggestions Their work and perspectives enhanced the accuracy clarity and value of these Guidelines

Peer Reviewers Dale E Dressel William (Skip) Early Ron Pertuit CSP Don Connolley 1 2

Company Solutia Early Consulting LC Eastman Chemical Co BP Not disclosed Not disclosed

Texas Operations

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

GLOSSARY

Accident

Acute

Aggregate Risk

Blast

Blast Load

BLEVE (Boiling Liquid Expanding Vapor Explosion)

Building

An unplanned event or sequence of events that results in an undesirable consequence

Single short-term exposure (less than 24 hours)

Societal risk for on-site workers in occupied buildings (API 752)

A transient change in the gas density pressure and velocity of the air surrounding an explosion point The initial change can be either discontinuous or gradual A discontinuous change is referred to as a shock wave and a gradual change is known as a pressure wave

The load applied to a structure or object from a blast wave which is described by the combination of overpressure and either impulse or duration

The explosively rapid vaporization and corresponding release of energy of a liquid flammable or otherwise upon its sudden release from containment under greater-than-atmospheric pressure at a temperature above its atmospheric boiling point A BLEVE is often accompanied by a fireball if the suddenly depressurized liquid is flammable and its release results from vessel failure caused by an external fire The energy released during flashing vaporization may contribute to a shock wave

A rigid enclosed structure

Building Siting The procedures used to evaluate the hazards and establish Evaluation the design criteria for new buildings and the suitability of

existing buildings at their specific locations

XXI

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases

XXII GUIDELINES FOR EVALUATING PROCESS PLANT BUILDINGS

Building Geographic Risk

Combustible

The risk to a person who occupies a specific building 24 hoursday 365 daysyear

Capable of burning

Confinement

Congestion

Consequence

Consequence Based Approach

Deflagration

Detonation

Essential Personnel

Explosion

Flammable

Flame Speed

Solid surfaces that prevent movement of unburnt gases and a flame front in one or more dimensions

Obstacles in the path of the flame that generate turbulence

The undesirable result of an incident usually measured in health and safety effects environmental impacts loss of property and business interruption costs For building siting consequence refers to building damage and occupant vulnerability from the potential effects of an explosion fire or toxic material release Consequence descriptions may be qualitative or quantitative

The methodology used for building siting evaluation that is based on consideration of the impact of explosion fire and toxic material release which does not consider the frequency of events

A propagating chemical reaction of a substance in which the reaction front advances rapidly into the unreacted substance but at less than sonic velocity in the unreacted material

A propagating chemical reaction of a substance in which the reaction front advances into the unreacted substance at or greater than sonic velocity in the unreacted material

Personnel with specific work activities that require them to be located in buildings in or near a process area for logistical and response purposes

A release of energy that causes a blast

A gas that can burn with a flame if mixed with a gaseous oxidizer such as air or chlorine and then ignited The term flammable gas includes vapors from flammable or combustible liquids above their flash points

The speed of a flame burning through a flammable mixture of gas and air measured relative to a fixed observer that is the sum of the burning and translational velocities of the unburned gases