E-Books: HAZOP-Guide to Best Practice Third Edition

This book is intended to provide guidance on a specific technique developed for use in the process and chemical industries. The technique described is HAZOP (hazard and operability) study, a detailed method for systematic examination of a well-defined process or operation,

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either planned or existing.

The HAZOP study method was developed by ICI in the 1960s and its use and development were encouraged by the Chemical Industries Association (CIA) Guide published in 1977. Since then, it has become the technique of choice for many of those involved in the design of new processes and operations. In addition to its power in identifying safety, health, and environmental (SHE) hazards, a HAZOP study can also be used to search for potential operating problems. Not surprisingly, the method has been applied in many ways within the process industries.

While it is frequently used on new facilities, it is now often applied to existing facilities and modifications. It has also been successfully applied to process documentation, pilot plant, and hazardous laboratory operations as well as tasks such as commissioning and decommissioning emergency operations, and incident investigation.

The objective here is to describe and illustrate the HAZOP study method, showing a variety of uses and some of the approaches that have been successful within the process industry. An important input has come from the European Process Safety Centre (EPSC) members where 22 member companies responded in a survey carried out prior to the first edition of this Guide (2000). This identified many features generally regarded as essential to a good study. In addition, many common variations were described.

E-Books: HAZOP-Guide to Best Practice’s cover

These variations are in part due to the range of problems encountered within the industry but also reflect individual choices of style. HAZOP study is a versatile technique and good results may be achieved by several different approaches provided the basic principles are followed. It is hoped that this Guide will help maintain a high standard for HAZOP study within the industry, both by raising quality and encouraging flexibility without putting any unnecessary constraints upon its use and development.

The HAZOP study method is well developed and is useful in most applications. There are other methods, however, that may have to be
considered depending on the complexity and hazards of the installation
being constructed and the state of the design. This publication does
not address these methods in detail but their importance is discussed
in Chapter 2. A fuller account is given in the IChemE Guide, Hazard
Identification Methods.
Finally, three illustrations of process industry applications are given
in Appendices 3, 4, and 5. These examples cannot fully represent all the
possible applications and process industries and readers new to HAZOP
study are advised to consult the reference list,3-6 the International
Electrotechnical Commission (IEC) standard,7 or guidelines written
specifically for other industries.
It is hoped that this guide will help people within the process industries, including all those with responsibilities within safety management systems. Although it is primarily written for HAZOP study leaders, scribes, and members, it may also be of use to those involved in training and plant management.