Hazard Identification & HAZOP (HAZard and OPerability studies) CHAPTER 4 Hazard Identification & HAZOP (HAZard and OPerability studies)

Hazard Identification Hazards are everywhere. Not always identified until an accident occurs. It is essential to identify the hazards and reduce the risk in before an accident occurs. In every chemical process, the following questions must be asked: What are the Hazards? Hazards Identification (This Chapter 4) What can go wrong and how? What are the chances? Risk Assessment (Chapter 6) What are the consequences?

Hazard Identification is part of “HIRARC” For Hazard Identification (HI), What are the hazards? Unsafe conditions? Unsafe act? For Risk Assessment (RA) (or Hazard analysis), What can go wrong and how? Also known as scenario identification. i.e. Events that can lead to accident What are the chances of accident to take place? i.e. The probability of those events occurring What are the consequences? i.e. This could include injury/fatality, loss of production/equipment, damage building/environment etc. Risk Control (RC) Modification of process/operation, Installation of control measures, Emergency response etc.

Definition of Hazard “Unsafe conditions and unsafe acts that could potentially cause accidents”

Definition of Unsafe Condition A hazardous physical condition or situations/circumstances, which could directly permit the occurrence of an accident. This could be the result of an unsafe act by someone.

Examples of Unsafe Condition Inadequate guards or protection Defective tools, equipment Congestion, bad housekeeping Inadequate warning system Fire and explosion hazards Hazardous atmospheric condition Excessive noise Inadequate light / illumination / air ventilation

Definition of Unsafe Act A violation of an acceptable safe procedure, which could permit the occurrence of an accident

Examples of Unsafe Act Operating without authority Operating at improper speed / power Making safety devices inoperable / damaging Using defective equipment Using equipment improperly Failure to use PPE (personal protection equipment) Improper loading, placement Servicing equipment in motion / switch-on Failure to warn or secure

Hazard Identification – How? Observing unsafe condition and unsafe acts that could potentially cause accidents. Conducting walk-through surveys, audits, check-list and inspections. Job Safety Analysis/Review. Examining documents and data.

When to perform hazard identification and risk assessment*? At the initial design stage. (ASAP to enable any modifications to be easily incorporated into the final design) During ongoing operation. Note: *Best result is obtained if hazard identification is performed together with risk assessment. This could also prevented “gold-plated” i.e. implementing unnecessary /expensive safety equipment and procedures.

Hazard Identification Methods Process Hazards Checklists Hazard Survey a. Inventory of hazardous material b. Dow indexes Dow Fire and Explosion Index Dow Chemical Exposure Index 3. HAZard and OPerability studies (HAZOP) 4. Safety Review

END OF PART 1 THANK YOU