Hazard Identification (HAZID) Methodology & Principles
HAZID is a technique for the identification of all significant hazards associated with the particular activity under
The process normally adopted is to firstly identify all the possible undesirable consequences that could occur and then to identify hazards which, when realized, would cause that consequence. It is usual to include in the hazard list all reasonably foreseeable hazards, without deciding whether each hazard poses a significant risk to the activity in question. Once the gross list of hazards has been established, each hazard is then reviewed to see whether it is significant and should be evaluated further.
A structured approach to the identification of undesirable consequences is normally adopted starting with the broad categorizations such as human impacts, environmental impacts and economic impacts.
Each of these categories can then be further subdivided by the type of resulting damage, for example, toxic exposure, thermal exposure, overpressure, mechanical force, radiation, electrical shock, etc. The more precisely the consequences of interest are defined, the easier it will be later to identify hazards. Checklists, hazard registers from similar activities and previous HAZIDs are frequently used in order to assist in the task of consequence identification and hazard identification.
Once the consequences of interest have been defined, the analyst can identify those system, process and plant hazards which, when realized, give rise to the consequence. Common methods for hazard identification include analysing process material properties and process conditions, reviewing organisation and industry experience, developing interaction matrices, and applying hazard evaluation techniques such as fault trees or coarse failure
modes and effects analysis. It is important at this stage to think as widely as possible in order to ensure that no foreseeable hazards are overlooked An alternative approach may also be used involving consideration of a list or register of all possible hazards as shown in annex D. Each hazard listed is assessed to determine whether it is relevant to the situations and activities being considered. At this stage no decisions are taken as to the importance or significance of the hazard, which is assessed later. All hazards identified as relevant are added to a gross list of hazards.
Once the gross list of hazards applicable to the particular situation has been prepared (either by the use of a hazard hierarchy or by consideration of consequences), each hazard is assessed to determine whether it is significant or not. Typical reasons for classification of a hazard as not significant are as follows:
very low frequency of occurrence, for example impact by asteroid;
insignificant effect on risk levels, for example release of gas from a pipeline a considerable distance from an installation;
the effect of realization of a hazard may be included in another more severe hazard.
It is important to record both the gross list of hazards and the reasons for classifying some as not significant. This allows easy reassessment of the hazards list in the event of changing process or operational conditions. All the risk dimensions (personnel, environment and assets) need to be carefully considered before hazards are classified as non-significant.
It is also normal practice to prepare a formal hazards register, detailing each hazard together with appropriate data such as potential cause, potential consequence, system, equipment and geographical location (as appropriate) and some form of identification reference. Where possible, hazards are often grouped to assist in reducing further computational effort.
Other forms of hazard identification techniques include:
Preliminary Hazard Assessment (PHA)
Job Hazard Analysis (JHA) / Job Safety Assessment (JSA)
Fault tree analysis (FTA)
Event tree analysis (ETA)
Hazard and operability analysis (HAZOP)
Failure modes and effects analysis (FMEA)
Physical-effects modelling (PEM)
Escape, evacuation and rescue analysis (EERA)
Quantitative risk assessment (QRA)
Safety integrity level (SIL) assessment
Safety Engineering Solutions has meaningful experience in all these techniques.
See link to HAZID Facilitator credentials.
Contact Safety Engineering Solutions today to find out how we can help you identify your hazards and manage the risk.