Hazard and Operability (HAZOP) Studies

Of the several “approved” types of Process Hazards Analysis (PHA), the “Hazard and Operability” (HAZOP) study is the most widely used PHA technique in the chemical, pharmaceutical, oil and gas, power generation and numerous other industries worldwide.


HAZOP is used during the design stages of a new process or project, for major process modifications, and for periodic review of existing operations. The HAZOP technique is very effective in identifying and analyzing the risks of potentially hazardous process operations, as well as identifying operability problems in both continuous and batch processing industries.

The Hazard and Operability (HAZOP) study methodology is a systematic team based (PHA) technique, which is accepted by regulators and industry around the world as appropriate for identifying and analyzing existing, new and potential hazards from complex processes that involves one or more highly hazardous substance(s). Our approach is to use structured HAZOP techniques to identify the hazards of a process, and as a by-product, to identify potential operating problems. The emphasis is on evaluating the basic control system, providing effective emergency controls, preventing the release of hazardous materials, and mitigating the consequences of a loss of process control or a hazardous-material release. HAZOP.EU provide a semi-quantitative HAZOP risk analysis that can incorporate the philosophies of Layers of Protection Analysis (LOPA), Safety Instrumented Systems (SIL), and Fault Tree Analysis (FTA) to assess the reliability of process controls and number and type of risk reduction measures (safeguards) that might be needed.

Although the HAZOP method is highly structured, in the application of Guide Words to Process Parameters, in practice, the quality of the study is influenced by the ability of the HAZOP Leader or Facilitator to ask the appropriate questions as well as guiding the study sessions with respect to depth and width of assessment and analysis. The objective is to ensure that the team identifies all the hazards of the process being studied, not only the most obvious hazards. Thus, the outcome of the study is based not only on the HAZOP study team’s knowledge and experience, but that of the HAZOP Leader’s with respect to the HAZOP technique, with the process being analyzed, with process-control systems and instrumentation, materials involved as well as with process and unit operations in general.

HAZOP.EU team of highly qualified HAZOP leaders and facilitators and process-safety resource experts has facilitated and lead many HAZOP-based PHA’s globally, in virtually all sectors of the process and processing industries. HAZOP.EU study leaders and facilitators are chemical and/or process engineers with a high level of process safety expertise and knowledge, and with many years of experience leading HAZOPs and other PHA studies in industry and consultancy environments.

HAZOP.EU predominately facilitate and lead HAZOPs, as well as other types of PHA studies in English. However, due to the global reach of our services, we conduct studies bilingually with local languages – this provides specific insight with local regulations, behaviors, customs and cultures etc. We conduct HAZOP studies, as well as other PHA studies, globally by the means of face to face (in-person), virtually (online) as well as using hybrid approaches (mixture of virtual and in-person sessions), depending on project requirements, budgets and timescales.

At HAZOP.EU we also provide HAZOP review/revalidation studies, delta or change HAZOPs, procedural HAZOPs, Management of Change (MOC) type HAZOP studies, as well as ‘HAZOP as a Service’ which is becoming more popular for resource limited projects and organizations who need to reduce their identified risks to tolerable levels. In addition to the conducting a HAZOP study, ‘HAZOP as a Service’ typical includes the post-HAZOP administration of action/recommendation and their management, follow-up/review and verification once complete.

If you want to discuss your HAZOP or PHA study requirements and how we could help you and your organization, please do not hesitate to contact HAZOP.EU. Alternatively, through the HAZOP.EU Process Safety Academy, we have trained and certified numerous HAZOP leaders/facilitators. We provide HAZOP leader training through our public-enrollment courses as well as private in-house company training, which can be tailored to our clients’ specific needs. Please contact HAZOP.EU if you would like to learn more about our HAZOP/PHA training courses or our Process Safety Academy in general.