Hazard and Operability Study

Hazard and Operability Study
Name	Hazard and Operability Study
Introduced	1960s
Developer	Imperial Chemical Industries
Field	Process safety

Contents

Introduction
Methodology
Applications and Industry Use
Benefits and Limitations
Case Studies and Examples
Regulatory and Standards Context
See also

Hazard and Operability Study is a structured technique developed for identifying potential hazards and operability problems in industrial processes and facilities. Originating in the 1960s, it has been applied across chemical, petrochemical, nuclear, pharmaceutical, and offshore sectors to reduce risk and improve design robustness. The method is associated historically with major organizations and incidents that shaped modern process safety practice.

Introduction

The method was formulated within Imperial Chemical Industries and gained prominence after adoption by companies such as Shell plc, BP, and ExxonMobil. It influenced procedures used by regulators like the United States Environmental Protection Agency and bodies such as Occupational Safety and Health Administration and European Chemicals Agency. Key incidents that accelerated uptake include the Flixborough disaster, the Texas City disaster, and the Bhopal disaster, which prompted reviews by institutions like the National Research Council (United States) and the Royal Society.

Methodology

The technique employs a multidisciplinary team drawn from organizations such as DuPont, Dow Chemical Company, BASF, and Chevron Corporation to examine process flows, equipment, and control systems. Typical inputs include process flow diagrams from firms like Siemens and Schlumberger, piping and instrumentation diagrams used by ABB and Honeywell, and operational data gathered by operators at facilities such as Ravenscraig steelworks or platforms like Brent oilfield. The structured questioning process parallels approaches in Safety Integrity Level assessment and shares features with methods like Failure Mode and Effects Analysis and Fault Tree Analysis. Outputs commonly include action items tracked against standards from American Society of Mechanical Engineers and procedures aligned with guidance from International Organization for Standardization.

Applications and Industry Use

Industries adopting the method include companies operating in sectors represented by International Association of Oil & Gas Producers, World Health Organization-influenced pharmaceutical plants, and utilities regulated under frameworks such as Federal Energy Regulatory Commission mandates. Use cases span greenfield design projects at yards operated by Samsung Heavy Industries, revamps at refineries like those once owned by ConocoPhillips, and decommissioning programs for sites overseen by agencies such as the Nuclear Regulatory Commission (United States). It is integrated with project management regimes practiced by corporations like Bechtel and Fluor Corporation.

Benefits and Limitations

Benefits cited by practitioners from organizations like Institution of Chemical Engineers and American Institute of Chemical Engineers include early identification of hazards, cross-disciplinary knowledge exchange, and documentation that supports compliance with laws such as the Clean Air Act and directives from the European Commission. Limitations noted in reviews by entities like National Safety Council and audits by PricewaterhouseCoopers include dependency on team expertise, potential for scope creep in projects managed by firms like Tata Steel, and challenges in quantifying residual risk comparable to assessments by Lloyd's Register. Complementary quantitative techniques from Sandia National Laboratories and Lawrence Livermore National Laboratory are often used to address probabilistic shortcomings.

Case Studies and Examples

Notable implementations include studies conducted for complexes linked to Shell plc in the North Sea and for processing units at facilities formerly under BP stewardship near Grangemouth. Industry case reviews appear in publications from Engineering News-Record and reports by consultants such as McKinsey & Company and Arthur D. Little. Project debriefs following events like the Deepwater Horizon oil spill and analyses by bodies including the Chemical Safety Board (United States) reference the method alongside tools used by KBR (company) and Mott MacDonald.

Regulatory and Standards Context

The method is cited in guidance from standards organizations including International Electrotechnical Commission, British Standards Institution, and American National Standards Institute, and is referenced in regulatory frameworks administered by Health and Safety Executive (United Kingdom), Environmental Protection Agency (United States), and national authorities such as National Industrial Chemicals Notification and Assessment Scheme. Its outputs support compliance with directives like the Seveso III Directive and reporting regimes under agencies including European Chemicals Agency.