HAZOP Checklist
Prepare Your Team, Documentation, and Scope Before the HAZOP Study
Half of what determines whether a HAZOP runs on schedule gets decided before anyone sits down at the table.
If the P&IDs handed to the team don’t match current conditions, or nobody can confirm the maximum intended inventory or operating capacity, the workshop stalls while someone tracks down the answer. That’s time the team doesn’t get back.
This HAZOP checklist focuses on four areas that can create problems during a study: incomplete or outdated documentation, an unclear study scope, missing technical expertise, and insufficient facilitator preparation.
What to Have Ready Before the HAZOP Workshop
Process Information and Documentation
Bring P&IDs that reflect the current design or actual field conditions, not drawings that no longer represent the process being reviewed. If a Block Flow Diagram (BFD) or Process Flow Diagram (PFD) is available, have that ready too, particularly where the P&ID alone does not make the overall process flow clear.
The team should have access to Safety Data Sheets (SDSs) and relevant chemical hazard information for the materials within the study scope. This may include flammability, reactivity, toxicity, corrosivity, and hazards associated with unintended mixing.
Safe operating limits for parameters such as temperature, pressure, flow, level, and concentration should also be documented, along with the potential consequences of operating outside those limits.
Have the control narrative and relevant information on alarms, interlocks, setpoints, detection systems, and other safeguards available for review. Where applicable, relief system design information should also be accessible so the team can understand the basis for existing overpressure protection.
Confirm maximum intended inventory and operating capacity before the workshop. Relevant codes, standards, and Recognized and Generally Accepted Good Engineering Practices (RAGAGEP) should also be identified where they form part of the design or operating basis.
Scope and Node Boundaries
Clearly document what is included in the HAZOP and what is not. This may include equipment, operating modes, interfaces with adjacent systems, study boundaries, exclusions, and assumptions.
If the facilitator and study participants have different interpretations of where the study starts and stops, that disagreement can surface during the workshop and take time away from the hazard review.
The design should also be mature enough for the HAZOP to produce meaningful results. Key process decisions, equipment configuration, control philosophy, and P&IDs should be sufficiently developed for the team to evaluate credible deviations without repeatedly revisiting fundamental design decisions.
Proposed HAZOP nodes can be developed in advance where appropriate. The facilitator can then review and refine the proposed boundaries based on the process, study scope, and level of detail required.
Team Composition
A HAZOP works because the right knowledge is represented in the room, not simply because the room is full.
Operations should be represented by someone familiar with how the process is actually operated. Engineering and technical expertise should match the systems and equipment being reviewed.
Depending on the study, additional subject-matter experts in areas such as instrumentation, controls, mechanical systems, electrical systems, chemistry, or maintenance may also be needed.
Participant roles should be established before the workshop so everyone understands what is expected during the study.
The team should also understand the risk-ranking criteria that will be used, where applicable. Establishing the approach beforehand avoids spending workshop time deciding how likelihood, consequence, or risk should be interpreted.
Facilitator and Workshop Preparation
Give the HAZOP facilitator access to the P&IDs, process description, scope, and supporting documentation early enough to review the material before the workshop.
This gives the facilitator time to understand the process, review the proposed scope and nodes, identify missing information, and raise questions before the full team is assembled.
The documentation method or HAZOP software should also be confirmed in advance.
For virtual or hybrid studies, test meeting access, screen sharing, and document availability before the first session. For in-person workshops, confirm that the meeting space, displays, and other equipment needed for the study are available and working.
Small logistical issues can become expensive when an entire multidisciplinary team is waiting for them to be resolved.
Download Your HAZOP Checklist PDF
The HAZOP Readiness Checklist brings these preparation areas together in one practical resource you can use before your next HAZOP study.
Use the checklist to review:
- P&ID currency and process documentation
- Chemical hazard information and safe operating limits
- Scope definition and design maturity
- Proposed node preparation
- Team composition and technical expertise
- Participant roles and responsibilities
- Risk-ranking criteria
- Facilitator preparation and workshop logistics
Each item can be marked Ready, Needs Attention, or N/A, with space for notes so outstanding items can be addressed before the study begins.
Complete the form below to download your HAZOP Checklist PDF.
Please note: This HAZOP checklist is provided as a general preparation resource. Requirements and preparation needs will vary depending on the process, facility, project stage, and study scope. It does not replace the judgment of a qualified HAZOP facilitator or process safety professional.
Frequently asked questions
What information is needed for a HAZOP study?
The information required depends on the process and study scope. Typical inputs include current P&IDs, a process description, chemical hazard information and SDSs, safe operating limits, and information on relevant alarms, interlocks, controls, and safeguards.
Depending on the process, additional information such as PFDs, equipment data, relief system design information, previous hazard studies, incident history, and other supporting process safety information may also be needed.
Who should participate in a HAZOP?
A HAZOP team should include people with the process knowledge and technical expertise needed to evaluate the systems within the study scope.
This typically includes operations and appropriate engineering representation, with additional subject-matter experts participating where their expertise is needed. An experienced HAZOP facilitator leads the study and keeps the team focused on systematically evaluating deviations, causes, consequences, and safeguards.
When should HAZOP preparation begin?
Preparation should begin early enough for the facilitator to review the process documentation, confirm the study scope, and identify missing information before the first session.
For larger or multi-day studies, this may mean beginning the review several weeks in advance. The appropriate lead time will depend on the size and complexity of the study and the condition of the available documentation.
Should HAZOP nodes be defined before the workshop?
Proposed nodes can be developed before the workshop where appropriate. The facilitator should review the proposed boundaries and refine them as needed based on the process, study scope, and level of detail required.
Node definition does not have to be completely finalized before the workshop, but advance planning can help the study begin more efficiently.
Planning a HAZOP Study?
Sigma-HSE provides HAZOP facilitation and Process Hazard Analysis (PHA) consulting for facilities preparing for new studies, revalidations, and other process hazard reviews.
Our process safety consultants can help define the study scope, review process documentation before the workshop, facilitate HAZOP sessions, and document findings and recommendations.
