Introduction to HAZID (Hazard Identification)

HAZID, also known as Hazard Identification, is a workshop-based qualitative risk analysis technique commonly used for the identification of potential hazards and threats in a process.

The purpose is to:

• Review the process at an early stage with a view to ensuring that the process design accounts for credible hazardous scenarios
• Review safeguards included in the design of the process which are designed to mitigate the relevant risk for the identified hazardous scenarios.

In order to conduct a successful HAZID workshop, it is important to involve a multi-disciplinary team familiar with the process and its operation. 

The study should be led by an experienced chair, with a scribe to record all identified hazardous scenarios, likely consequences, safeguards and actions.  The effectiveness of the HAZID (and similar studies) relies heavily on the experience of the workshop team to ensure that relevant foreseeable scenarios are captured.

When to Conduct a HAZID?

HAZID is likely to be one of the first formal HSE-related studies for any new project and is normally performed at the early design stage of a project.

The major benefit of conducting a HAZID at this time is the early identification of high consequence hazards providing essential input to project development decisions before the design reaches its final stages. This will lead to safer and more cost-effective design options being adopted with a minimum cost of change penalty.

It is a flexible risk analysis technique that can be used at any time in the lifecycle of a plant, from early project life to decommissioning. For example, HAZID analyses are often used for Management of Change where modifications, upgrades, or re-design of existing facilities are carried out.

Is HAZID the appropriate technique?

The high-level nature of a HAZID is suitable for reviewing the design at an early stage without requiring in-depth knowledge of the operation.

In some cases, a What-If? analysis may be more appropriate.  What-If? is an alternative risk analysis technique which is generally suited to smaller or less complicated processes or to review specific scenarios of a more complex process as the analysis technique requires hazardous scenarios to be identified prior to the workshop.  The What-If? technique however allows consideration of scenarios in greater detail, whereas HAZID tends to cover a wider range of scenarios in less detail.

The final technique for design review is HAZOP (Hazard and Operability Study), this is a much more detailed and structured form of hazard assessment that should be undertaken once a detailed design is in place and the team have a thorough understanding of the operation.  If conducted too early in the design process, the HAZOP is unlikely to be sufficiently comprehensive due to a lack of information and would need to be revisited. 

A HAZID (or What-If?) should always be the first study undertaken on a new design, as early as possible in the design process.  The HAZOP should then be considered once the design is confirmed, and the way in which equipment is to be operated is understood. 

Table 1: Summary of different Process Hazard Analysis techniques.

HAZID Process          

For the HAZID workshop, the operation is divided into manageable, logical sections (systems, units or nodes). Section limits are often identified by a significant change in the process conditions, a change in location or in material phase and composition. Divisions of a complex facility, for example, can be processing units, but less comprehensive facilities could also be subdivided into functional groups.

A HAZID study typically follows the sequence illustrated below (Figure 1).

Common HAZID guidewords and considerations are listed in the table below. Guidewords and considerations can be added/removed to reflect various operations.

Table 2: Example of select HAZID guidewords and considerations.

To learn more about Process Hazard Analysis please click here

To connect with the author, Alex Cooke, please visit his LinkedIn profile.

---