Onshore terminals — gas processing facilities, pipeline terminals, and bulk liquid storage sites — operate under the same process safety obligations as offshore installations. The regulatory framework is equally demanding. The safety culture, in many cases, is not.
The reasons are partly historical. The major advances in process safety management over the past three decades were driven largely by offshore incidents — Piper Alpha, Macondo, and the regulatory responses that followed.
The offshore sector developed a safety culture, an inspection regime, and a set of management expectations that onshore terminals have not always kept pace with. The hazards are comparable. The maturity of the management systems often is not.
That gap is where incidents happen — and where regulators are increasingly focusing their attention.
The regulatory framework
Onshore terminals handling flammable, explosive, or toxic substances above defined threshold quantities are subject to the Control of Major Accident Hazards Regulations 2015 — COMAH. The competent authority for COMAH is a joint team of the HSE and the Environment Agency. Upper tier COMAH sites — those handling the largest quantities of hazardous substances — are required to produce a safety report, implement a safety management system, and demonstrate to the competent authority that major accident hazards are being controlled effectively.
The COMAH safety management system requirement is directly comparable to the safety case requirement for offshore installations. It requires the operator to identify major accident hazards, define the controls that prevent them, and demonstrate that those controls are functioning as intended. The demonstration requirement is the part that many onshore terminal operators find most challenging — not because the controls do not exist, but because the evidence that they are working is not systematically generated or maintained.
Where onshore terminal PSM fails
The failure patterns in process safety management at onshore terminals are well-documented by the HSE and the competent authority. They differ from offshore failures in degree rather than kind — the same underlying issues, in an environment where the scrutiny has historically been less intense.
Process hazard analysis findings are not tracked to closure. A HAZOP or HAZID study identifies actions — engineering changes, procedural updates, additional safeguards. Those actions are documented in the study report. Whether they are completed, by whom, and by when, is not systematically tracked in a way that gives operations management confidence that the barrier identified in the study actually exists.
Safety critical equipment is not managed to a defined performance standard. The equipment that prevents or limits major accidents — pressure relief devices, emergency isolation valves, fire and gas detection, deluge systems — requires periodic testing and verification to confirm it will perform when needed. At many onshore terminals, this testing is managed within a general maintenance programme without the specific performance standard tracking that SCE management requires.
Management of change is inconsistently applied. Modifications to plant, process, or operating procedures that affect major accident hazards require a formal MOC process that assesses the impact on the safety case or safety report before the change is implemented. In practice, MOC is often applied rigorously to large capital projects and inconsistently to the smaller operational changes — a revised operating limit, a temporary bypass, a changed inspection frequency — that individually appear minor but cumulatively degrade the safety barrier.
Permit to work is treated as an administrative function rather than a safety critical control. At onshore terminals with lower operational tempo than offshore assets, the permit to work system can become a compliance exercise — forms completed because they are required, not because the control is actively maintained. Isolation quality, concurrent work management, and reinstatement discipline decline when the permit is treated as paperwork rather than as the mechanism that keeps people safe.
The inspection and verification gap
One of the most consistent findings in COMAH competent authority inspections is the gap between what the safety management system describes and what actually happens on the site. The procedure says that SCE performance is reviewed quarterly. The records show that the last review was eleven months ago. The procedure says that MOC assessments are completed before changes are implemented. The records show assessments completed weeks after the change went live.
This gap is not usually the result of deliberate non-compliance. It is the result of a safety management system that depends on individual memory and manual processes to function — and that degrades quietly when operational pressures increase and safety management tasks compete with production priorities.
A competent authority inspector who finds this pattern is not just recording a documentation failure. They are identifying a system that is not providing the assurance it claims to provide — and a site where the major accident barriers may not be performing as the safety report assumes.
What good process safety management looks like at an onshore terminal
The characteristics of effective PSM at an onshore terminal are the same as anywhere else — but they are worth stating specifically in this context because the baseline at many sites is lower than it should be.
PHA actions are tracked in a system that provides operations management with a live view of what is open, what is overdue, and who owns each action. The PHA study is not a document that sits in a folder — it is a living record that drives the assurance programme.
SCE performance is monitored continuously, not reviewed periodically. Every SCE has a defined performance standard. The maintenance and inspection programme is connected to those standards. Overdue activities are visible as SCE performance gaps, not just as maintenance backlog.
MOC is applied consistently to all changes that affect major accident hazards — including operational changes, temporary modifications, and changes to operating limits — not just to capital projects.
Permit to work is actively managed, with real-time visibility of all active permits and isolations, formal concurrent work conflict checking, and reinstatement discipline enforced by the system rather than dependent on individual competence.
And the evidence that all of this is functioning is generated automatically — not assembled manually when an inspection is scheduled.
A practical self-assessment
These questions will give you an honest read of where your onshore terminal PSM stands:
- Can you produce a current list of all open PHA actions, with owners and due dates, within five minutes?
- Are SCE performance standards connected to your maintenance and inspection programme, or managed as a separate exercise?
- In the last twelve months, has any operational change been implemented before the MOC assessment was completed?
- Does your permit to work system provide real-time visibility of all active permits and isolations, or does establishing that picture require manual effort?
- If the COMAH competent authority arrived tomorrow, could you demonstrate — from live system data rather than manually assembled reports — that your safety management system is functioning as described?
If any of those questions are difficult to answer confidently, the gap between your documented safety management system and its actual performance is real — and it is the gap that competent authority inspections are specifically designed to find.
How Elisian supports onshore terminal PSM
Elisian's platform is deployed across onshore and offshore energy assets, supporting the full range of process safety management functions — PHA action tracking, SCE performance management, management of change, permit to work, and operational assurance — in a single integrated system.
For onshore terminal operators who are preparing for a COMAH inspection, addressing findings from a previous inspection, or simply looking to close the gap between their documented safety management system and what is actually happening on site, Elisian provides the visibility and the evidence base that effective PSM requires. Get in touch with the Elisian team to find out more.