Hazop

HAZOP is an abbreviation for HAZard and OPerability analysis. Originally developed for use at manufacturing facilities such as oil refineries, offshore oil platforms, petrochemical and chemical plants, natural gas processing plants and power plants, its application has expanded to other areas as well. It is a systematic method for examining complex facilities or processes to find actual or potentially hazardous procedures and operations so that they may be eliminated or mitigated. HAZOP Studies are performed by a team consisting of plant operators, engineers, managers and others, some of whom should be intimately familiar with the facility being studied.

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The origins of HAZOP Studies are in the British chemical industry and its adoption was driven by the 1974 Flixborough explosion, where lack of a systematic review of modifications by appropriately qualified personnel was identified as a contributing factor.

Methodology

The methodology may be applied to any process or project although most practitioners and expertise originate in the chemical and offshore industries. A HAZOP uses guide words (e.g. "more", "less", "as well as") and parameters (e.g. "temperature", "control", "ventilation") to consider process intent, possible deviations from the intended process, the consequences of any deviations, and the hazards presented by these consequences.^[1][2][3] The following table gives an overview of commonly used guide word - parameter pairs and common interpretations of them.

Once the causes and effects of any potential hazards have been established, the system being studied can then be modified to improve its safety.

See also

• Hazard analysis
• Hazard Analysis and Critical Control Points
• Process Safety Management
• Risk assessment
• Safety engineering

References

1. ^ Center for Chemical Process Safety (1992). Guidelines for Hazard Evaluation Procedures, with Worked Examples, 2nd Edition, Wiley-AIChE. ISBN 0-8169-0491-X. 
2. ^ Vesely, W.E., Goldberg, F.F., Roberts, N.H. and Haasl, D.F. (1981). Fault Tree Handbook. U.S. Nuclear Regulatory Commission. NUREG-0492.  Nuclear Regulatory Commission (Pdf file)
3. ^ Kletz, Trevor (1999). Hazop and Hazan, 4th Edition, Taylor & Francis. ISBN 0-85295-421-2.