Hazid is a high-level hazard identification technique generally done in the early stages of the design of a project. The intent of Hazid is to identify the significant hazards associated with a particular plant, section or unit operation under consideration by utilising a series of checklists or What If questions based on agreed generic failure modes of process, equipment, environment, people and materials


The Hazid is a feeder to the risk assessment in that the main failure scenarios are identified in the Hazid and are then taken on to be further developed and assessed in the Risk Assessment.

The facility being assessed is broken down into systems and the guidewords, What if questions are applied to each section.

The history of the facility / process being examined is an important starting point as any events that have impacted the facility / section at the site or in the industry should be examined to confirm that the causes that led to the event have been covered by the design / improvement being proposed

High level guide words / checklist items for process plant would include

  • Leaks of materials from pipework
  • Major failures of tanks, pressure vessels etc
  • Reaction hazards, mixing/ exothermic runaways etc
  • Internal explosions
  • External fires/ explosions following leaks


ProSalus has assisted a number of our clients in carrying out Hazids using either their prepopulated checklists or by applying generic industry specific checklists