A Hazard and Operability (HAZOP) study identifies hazards and operability issues, but recommendations are what convert those findings into actual risk reduction. Weak or vague recommendations dilute serious findings, delay implementation, and fail audits. Strong recommendations, on the other hand, are clear, stand-alone, SMART, and focused on reducing risk to a tolerable level.
This guide presents practical, industry-aligned guidelines for writing effective HAZOP recommendations, supported by clear examples and aligned with professional HAZOP best practice.
1. Purpose of a HAZOP Recommendation
A HAZOP recommendation has one purpose only to reduce risk. If a recommendation does not clearly reduce either the likelihood of an initiating event, or the severity of the consequence, then it should not be written.
Good example:
“Install an independent high-pressure trip on reactor R-01 to isolate feed and prevent vessel rupture.”
Poor example:
“Improve reactor safety.”
HAZOP is not a design review, optimization study, or maintenance wish list. Recommendations must directly address the identified hazard scenario.
2. When a Recommendation Should Be Raised
A recommendation should be raised when:
- No effective safeguard exists
- Existing safeguards are not independent, reliable, or credible
- Residual risk remains above the company’s tolerable risk criteria
- Safeguards exist but are informal, undocumented, or poorly defined
- Operability issues threaten safety, environment, quality, or availability
Example:
If vessel overfill protection relies only on operator response to a low-priority alarm, a recommendation is justified.
If risk is already tolerable with robust safeguards, no recommendation is required. Too many minor recommendations dilute the importance of significant findings.
3. Characteristics of a Good HAZOP Recommendation
A good HAZOP recommendation defines a course of action, not a detailed engineering solution.
- It should be Clear and specific, Actionable, Root-cause focused, Achievable and Verifiable, with a clear point of closure
- Avoid vague or emotive language such as consider, improve, or ensure. Use precise action words like install, modify, provide, or evaluate and document.
Poor Example : “Solve corrosion problem.”
Good Example: “Evaluate corrosion mechanism on line L-102 and implement appropriate corrosion mitigation to prevent loss of containment.”
4. Stand-Alone Recommendations (Mandatory)
Every HAZOP recommendation must be stand-alone. This means it must be fully understandable without referring to the HAZOP worksheet and clearly state what must be done and why. A reviewer should immediately understand, the hazard, the required action, and the intended risk reduction. Stand-alone clarity is essential for audits, follow-up reviews, and long-term tracking.
Not stand-alone:
“Add protection as discussed.”
Stand-alone:
“Install an independent high-level trip on separator V-01 to shut down feed pump P-01 and prevent liquid carryover to the downstream compressor.”
5. SMART HAZOP Recommendations
HAZOP recommendations should follow SMART principles, adapted for process safety applications.
Specific – Clearly define equipment, tag numbers, action, and hazard.
Weak: “Improve exchanger performance.”
Strong: “Install a parallel heat exchanger with EE-01 to prevent high feed temperature during summer operation.”
Measurable – Closure must be verifiable (installation complete, logic tested, procedure approved).
Achievable – Actions must be technically feasible and realistic.
Poor: “Redesign entire unit.”
Good: “Install a second parallel exchanger to supplement EE-01.”
Risk-Reducing – The recommendation must reduce likelihood or consequence.
Example: A parallel exchanger reduces overheating and downstream upset risk.
Traceable / Time-Bound – Each recommendation must be traceable to the node, deviation, cause, and consequence, and assigned an owner with a target date.
6. Recommended Writing Structure
To ensure recommendations are both stand-alone and SMART, use the following structure:
Action + Equipment/Tag + Condition + Purpose
Example:
“Install an independent high-pressure trip on V-01 to isolate feed when pressure exceeds design limits and prevent vessel rupture.”
7. Types of HAZOP Recommendations
Recommendations should be classified and numbered sequentially, regardless of type, such as:
- Safety-related
- Environmental
- Operational / operability
- Drawing or documentation updates
- Operating procedure updates
- Register updates (alarms, trips, safety devices)
- HAZOP team follow-up items
Engineering recommendations should always take priority over administrative controls.
8. Engineering vs Procedural Recommendations
Engineering safeguards (preferred): Trips, interlocks, relief devices, independent alarms. Example: “Install high-high pressure trip to shut down compressor.”
Procedural controls (last resort): Acceptable only for low-risk scenarios. Example: “Update startup procedure to include manual pressure verification.”
Procedures alone must never be relied upon to protect against high-risk hazards.
9. Independence Check (Critical)
Safeguards and recommendations must be independent of: the initiating cause, other credited safeguards, and shared power, logic, or sensors. Example: An alarm and trip using the same pressure transmitter are not independent.
10. Team Consensus on Recommendations
The HAZOP leader must drive consensus on: what must be done, and why it must be done. Teams often struggle when they attempt to design detailed solutions instead of agreeing on the required action. Once agreed, recommendations must not be changed without team concurrence.
11. When Recommendations Are Not Needed
Minor issues such as drawing corrections, minor documentation updates, or routine procedure edits should not dilute major risk findings and are often tracked separately. However, repeated minor issues may justify one higher-level recommendation addressing systemic weaknesses.
12. Assignment, Closure, and Management of Change
- Every recommendation must include: an owner, a target completion date, and a status (open, closed, deferred).
- A recommendation is closed only when the action is implemented, documentation is approved, or risk is formally accepted. Any change affecting process conditions, equipment, control logic, or safeguards must go through Management of Change (MOC).
Certified Functional Safety Professional (FSP, TÜV SÜD), Certified HAZOP & PHA Leader, LOPA Practitioner, and Specialist in SIL Verification & Functional Safety Lifecycle, with 18 years of professional experience in Plant Operations and Process Safety across Petroleum Refining and Fertilizer Complexes.
