2. Contents
HAZARD AND RISK IDENTIFICATION
• Job Hazard Analysis (JHA)
• Process Hazard Checklist
• Hazard Survey
• Hazard and Operability Studies (HAZOP)
• Chemical Health Risk Assessment (CHRA)
• Fault Tree Analysis
• Failure Mode Event Analysis
3. Causes Of Accident &Incident
• Incidents and Accidents are caused by either unsafe
behaviours (substandard practice) and/or unsafe conditions
(substandard designs).
Unsafe behaviors are handled by Occupational Safety
Program.
Unsafe conditions are managed through Process Safety
Programs.
12. Qualitative RiskAnalysis
•Process Hazards Analysis is the
predictive identification of hazards,
their cause & consequence and the
qualitative estimation of likelihood
and severity.
14. Process HazardAnalysis
PHA allows the employer to:
•Determine locations of potential safety
problems
• Identify corrective measures to improve safety
•Preplan emergency actions to be taken if safety
controls fail
15. PHA must address the folowing:
• The hazards of the process
•Identification of previous incidents with likely potential
for catastrophic consequences
•Engineering and administrative controls applicable to the
hazards and their interrelationships
•Consequences of failure of engineering and
administrative controls, especially those affecting
employees
• Facility siting; human factors
•The need to promptly resolve PHA findings and
recommendations
17. • Review an installation against known hazards
identified on previous studies of similar plant
• Examine the checklist for relevance to plant
being studied
• Ask questions based on a pre-defined list
• The checklist is a corporate memory of what
could go wrong
• Should be augmented by industrial-wide
experience when available
18. Strength ofChecklist
• Is quick and simple to perform and is easily
understood
• Makes use of existing experience and
knowledge of previous systems
• Helps check compliance with standard practice
and design intention
• Ensures that known hazards are fully explored
19. Weakness ofChecklist
• Does not provide a list of initiating events (failure
cases) for a QRA.
• May not be comprehensive and does not
encourage analysts to consider new or unusual
hazards.
• Highly dependent upon the quality of the
prepared checklists.
20. Checklist QuestionCategories
• Causes of accidents
• Process equipment
• Human error
• External events
• Facility Functions
• Alarms, construction materials, control systems,
documentation and training, instrumentation,
piping, pumps, vessels, etc.
21. ChecklistQuestion
Causes of accidents
- Is process equipment properly supported?
- Is equipment identified properly?
- Are the procedures complete?
- Is the system designed to withstand hurricane winds?
Facility Functions
- Is it possible to distinguish between different alarms?
- Is pressure relief provided?
- Is the vessel free from external corrosion?
- Are sources of ignition controlled?
24. Step1: PreparetoconducttheJHA
• Review all the job in the workplace and make a list of
those jobs that might require a JHA.
• Get involve your employees.
• Look for hazards conditions and unsafe behaviors :
• MSDS
• Experienced workers
• Previous accident report
• Equipment manual, etc.
