Hazard and Operability Study (HAZOP) Analysis and Evaluation

This report provides a comprehensive analysis of Hazard and Operability Study (HAZOP), a systematic method for identifying potential hazards and operability problems within a system. It begins with a historical overview of HAZOP's development, followed by a definition and a comparison with other risk assessment techniques like LOPA and QRA. The report then delves into the HAZOP methodology, including its terminology and application. It explains when and where HAZOP is carried out, discusses its advantages and disadvantages, and concludes with a detailed case study example. The case study focuses on the Texas City Refinery explosion to illustrate the practical application of HAZOP in identifying and mitigating risks. This report aims to provide a thorough understanding of HAZOP's principles and its significance in ensuring process safety.

Running head: HAZARD AND OPERABILITY ANALYSIS (HAZOP)
Hazard and Operability Study (HAZOP)
Name of the Student
Name of the University
Author Note

1HAZARD AND OPERABILITY STUDY (HAZOP)
Executive Summary
Environment is considered to be one of the most essential sources for the survival of
the human beings on the planet Earth. It is the place on Earth where all forms of living as
well as the non-living organisms survive. In the recent years, HAZOP has been used to assess
the potential threats which are present in a situation and to find the possible alternative
solutions to the problems. This report will look at the definition of HAZOP as well as its
functions and how it id different from QRA and LOPA.

2HAZARD AND OPERABILITY STUDY (HAZOP)
Table of Contents
Introduction................................................................................................................................3
Discussion..................................................................................................................................4
History of HAZOP.................................................................................................................4
Definition and Difference with LOPA and QRA...................................................................5
HAZOP Methodology............................................................................................................6
Terminology...........................................................................................................................6
When and Where is HAZOP Carried Out?............................................................................7
Advantages and Disadvantages..............................................................................................7
Case Study Example..............................................................................................................8
Conclusion..................................................................................................................................8
Reference List............................................................................................................................9

3HAZARD AND OPERABILITY STUDY (HAZOP)
Introduction
When the term HAZOP is referred, it means a method of critical examinations by a
team of experienced examiners to identify the various threats that are present in a particular
area or in different areas of an equipment and the potential dangers that it might present to the
society itself. The concept is based on the theory that the risks in an equipment are caused by
the deviations which are caused in the making of the equipment that are separate from those
of the operational intentions. Therefore, this report will consider the workings of HAZOP as
well as provide a case study example of HAZOP to describe the how the process of HAZOP
works in the industry itself.
Discussion
History of HAZOP
The technique of HAZOP is said to have originated in the Heavy Chemicals Divisions
of the ICI, which then at the time was considered to be an important British as well as
international chemical company. It has been stated by the safety advisor that in the year 1963,
a team of three people started studying the designs of a new chemical plant. Although these
people started their study with a critical understanding of the process of the chemical plant
design, they soon looked for deviations for different way of studying the designs themselves.
The company made additional modification to the methods and the name operability studies.
In this way, the first steps towards the formation of the HAZOP, was taken by the team of
experts (De la O Herrara, 2016).
Later, it was known rom the archives of the ICI, that a one week safety course for the
testing of the procedure was made in the year 1974. In that same year, the first paper on the
introduction of the HAZOP method was published thereby, making the public aware of the
processes of HAZOP. The first-time HAZOP methodology was properly published for the

4HAZARD AND OPERABILITY STUDY (HAZOP)
audiences by Trevor Kletz in the year 1983. The readers get to know the fact that by the time
the proper document was published, the method had become popular among the public and
an expected part of the chemical engineering degree courses in the United Kingdom itself.
This forms the history of the origin of the HAZOP method.
Definition and Difference with LOPA and QRA
A Hazard and Operability Study (HAZOP) is considered to be a structured as well as
a systematic examination of the problems which might cause to be a problem for the people
or employees who work in the company itself. The technique is considered to be qualitative
in nature itself and its main aim is to use the imagination of the people participating in the
process to help identify the threats which are present in the system itself. It is therefore
mainly for the purpose of batch processing as well as the operating procedures (De La O
herrara, 2015). It is because of these reasons that the HAZOP is considered to be one of the
best ways of removing the threats which are present in the chemical power plants and other
equipment in the industry itself.
The main objective is considered to make the difference between the HAZOP with
that of the LOPA and that of QRA. In this case, it is seen that the main difference between
the HAZOP and LOPA is that HAZOP is a type of LOPA which is mainly concerned with
the question of determining if the level of the risk detected is tolerable, with the amount of
safety measures that are available in the system (Nolan, 2014). On the other hand, LOPA is
mainly concerned with the detailed level of analysis which can identify risks and provide
solutions to them a d considered to be better than PHA. HAZOP is considered to belong to
the category of LOPA which is why, it is said to be LOPA/HAZOP (de la O harrara, 2017).
Similarly, the difference between the HAZOP and that of QRA is that QRA (Qualitive
Risk Assessment) is mainly concerned with the quantative methods to assess the risks and

5HAZARD AND OPERABILITY STUDY (HAZOP)
suggest methods to prevent such methods from occurring again. On the other hand, HAZOP,
mainly deals with the subject matter of the risks associated with the equipment itself.
HAZOP Methodology
The HAZOP methodology is considered to be the most common method for
identifying and analysing the evaluations of the process from each other. Therefore, it
can be said to be one of the best methods of the identifying the hazards available in
the workplace itself (Ismite, 2016). For this purpose, the nodes are chosen so that the
meaningful design intent can be generated as well as can be documented in the
process flow diagram. The team uses a number of nodes to make sure that the nodes
used in the HAZOP remains the same. These processes made by the experts can help
to decide the manner in which the risks can be taken down to an acceptable level by
the experts (Rubini, 2016).
Therefore, the use of HAZOP technology can be used for the overall success of the
process itself. The team members can also focus on the normal tasks during this time while
the HAZOP team members need to focus on refreshing their mental capabilities.\
Finally, the methodology section of the HAZOP can be concluded with the statement
that the success of the HAZOP process mainly depends on the alertness and the concentration
level of the members of the team themselves and the various ways in which the members of
the team work together in solving the deviations in the power plants itself.
Terminology
The terminology of the HAZOP methodology are as follows: -
NO OR NOT – Complete not acceptance of the process of the design.
MORE – Increase

6HAZARD AND OPERABILITY STUDY (HAZOP)
LESS – Decrease
AS WELL AS – Increase
PART OF – Decrease
REVERSE – Opposite
INSTEAD – Alternative
EARLY – Relative to the clock time/ Before.
LATE - Relative to the clock time/ After.
BEFORE – To the order of sequence.
After – To the order of sequence.
When and Where is HAZOP Carried Out?
HAZOP is generally carried out in the industrial areas where there are risks of the
equipment industrial areas facing a number of threats in the industry itself. It is in such areas
that the people who run the industry feel the need of the HAZOP so that the process can be
more effective ibn carrying out its process effectively which can result in the number of the
thetas being removed successfully and the elements in the industry can be taken on the basis
of the HAZOP which can be useful in such situations. Therefore, it can be said that the
HAZOP methodology will be used for the purpose of the industries and the reduction of the
levels of the waste in the industry itself (Ahn et. all, 2015). Thus, it is in such areas, that the
HAZOP methodology is being carried out by the experts themselves in this matter.
Advantages and Disadvantages
The advantages of the HAZOP process are as follows: -
1.The process is part of a systematic examination to assess the threats in the industry.

7HAZARD AND OPERABILITY STUDY (HAZOP)
2.HAZOP can cover the errors made by the people.
3.The results obtained from studying HAZOP’s can be recorded by the experts.
4.The team members can easily learn and carry the processes of HAZOP.
The disadvantages of the HAZOP process are as follows: -
1.It focuses on the single events instead of a number of events.
2.Mainly focus on guide words, cannot work other than guide words.
3.More training is required.
4.Time consuming.
Case Study Example
The Case Study using HAZOP methods can be explained by using the example of the
Texas City Refinery as well as the blasts which occurred at the Texas City Refinery in the
year 2005. The case study in this method was carried out to understand the various causes
which had led to the blasts in the Texas City Refinery in the year 2005.
Using the HAZOP as a basis of the case study, it can be stated that the procedure
found the causes responsible for the blasts itself and the various ways in which the elements
of the industry could be checked so that the threats could be brought at a tolerable level by
the experts themselves (Crawley et. all, 2015).
Conclusion
From the above discussions, it can be concluded that the HAZOP methods indeed
focus on the reduction of the level of threats in the industries and other power plants where
they can help the experts in understanding the point on whether the elements needed to be

8HAZARD AND OPERABILITY STUDY (HAZOP)
brought at a tolerable level or whether the elements are at a tolerable level themselves. This is
what is mainly dealt with by the HAZOP processes in the country itself.

9HAZARD AND OPERABILITY STUDY (HAZOP)
Reference List
Ahn, J., & Chang, D. (2016). Fuzzy-based HAZOP study for process industry. Journal of
hazardous materials, 317, 303-311.
Crawley, F., & Tyler, B. (2015). HAZOP: Guide to best practice. Elsevier.
de la O Herrera, M. A., Luna, A. S., da Costa, A. C. A., & Lemes, E. M. B. (2015). A
structural approach to the HAZOP–Hazard and operability technique in the
biopharmaceutical industry. Journal of Loss Prevention in the Process Industries, 35,
1-11.
Isimite, J., & Rubini, P. (2016). A dynamic HAZOP case study using the Texas City refinery
explosion. Journal of loss prevention in the process industries, 40, 496-501.
Nolan, D. P. (2014). Safety and security review for the process industries: Application of
HAZOP, PHA, what-if and SVA reviews. Elsevier.
Othman, M. R., Idris, R., Hassim, M. H., & Ibrahim, W. H. W. (2016). Prioritizing HAZOP
analysis using analytic hierarchy process (AHP). Clean Technologies and
Environmental Policy, 18(5), 1345-1360.
Pérez-Marín, M., & Rodríguez-Toral, M. A. (2013). HAZOP–Local approach in the Mexican
oil & gas industry. Journal of Loss Prevention in the Process Industries, 26(5), 936-
940.

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Tian, W., Du, T., & Mu, S. (2015). HAZOP analysis‐based dynamic simulation and its
application in chemical processes. Asia‐Pacific Journal of Chemical Engineering,
10(6), 923-935.