Process Safety and Plant Operation

On too many sites, process safety studies have quietly become a paperwork exercise. The HAZOP report sits in a folder, the actions closed on a spreadsheet nobody has opened since, and the hazardous area drawings show a plant that no longer exists. Then a modification goes in, a new solvent is introduced, and the assessments meant to control the risk have not kept pace with the plant.

Projex Solutions provides process safety and plant operation support to regulated manufacturers across the UK: chemical, pharmaceutical, food and drink, FMCG and energy sites. We chair and scribe the studies, produce the assessments and drawings, and help you act on what they find. Our engineers work in design and in operations, so recommendations are written to be built and maintained, not filed. Where a study identifies a required safeguard, we can specify, design and verify it. Where none is needed, we will say so.

What we cover

• HAZID – qualitative hazard identification run early in a project, flagging chemical, mechanical, utility and external-event hazards before the design is fixed.
• Process Hazard Review (PHR) – an early-stage review of process descriptions, deviations and safeguards, producing a risk register for concept design and change management.
• HAZOP facilitation (chairing and scribing) – independent chairs and scribes who run the guide-word analysis across PFDs and P&IDs and deliver a traceable, actioned report.
• LOPA – semi-quantitative analysis of high-risk scenarios, testing initiating event frequency against the independent protection layers to judge whether residual risk is tolerable.
• SIL determination, verification and design – setting the integrity level each safety instrumented function requires, then proving the proposed sensors, logic solvers and final elements achieve it.
• Functional safety – safety lifecycle support to BS EN 61511: requirement specifications, safety logic and cause-and-effect design, validation, proof testing and maintenance strategy.
• DSEAR assessments – site surveys identifying dangerous substances and ignition sources, review of ventilation and mitigation, and a report with a risk register and prioritised actions.
• Hazardous area classification (HAC) assessment and drawings – release source identification and zone extent assessed to BS EN IEC 60079, with CAD zone drawings and a supporting report.
• ATEX compliance – verification that installed equipment carries the correct certification and marking for its zone, plus explosion protection documents.
• CompEx inspection – visual, close and detailed inspection of hazardous area electrical equipment by CompEx-qualified inspectors, with a prioritised non-conformance report.
• Lightning protection – risk assessment, external protection using air terminals, down conductors and earthing, and surge protective devices for control and instrumentation.
• Process manufacturing improvements – debottlenecking, control and automation upgrades, energy efficiency work and material handling redesign that lift throughput and remove known risks.

How the studies fit together

Buyers frequently ask for a HAZOP when what they need sits either side of it. The studies form a sequence, each answering a different question. Hazard identification comes first: a HAZID or a Process Hazard Review asks what could go wrong here, while the answer can still influence layout, materials and control philosophy. A HAZOP comes later, once P&IDs are firm, and asks how could this line or vessel deviate from design intent.

A HAZOP usually surfaces a few scenarios where the consequence is severe and the safeguards are not clearly sufficient. Those go to LOPA, which asks is the protection we have good enough, counting the credible independent protection layers and comparing residual risk against your criteria. Where LOPA shows a shortfall that instrumentation must close, SIL determination sets the performance target for that function. SIL verification proves the proposed architecture, diagnostics and proof test interval can deliver it, and functional safety carries the loop into operation.

Hazardous area classification and DSEAR run alongside that sequence rather than inside it. HAC establishes where flammable atmospheres can form and to what extent, which drives zone drawings and equipment selection. DSEAR is the wider legal duty covering dangerous substances on site, and takes HAC as an input. ATEX compliance, CompEx inspection and lightning protection all follow from the zoning. If you are unsure which study you need, describe the situation and we will tell you.

When clients typically call us

• A HAZOP is overdue for revalidation, or the last one predates several modifications.
• An inspection, COMAH assessment or insurer audit has raised findings on process safety documentation.
• A DSEAR assessment or hazardous area drawing set is missing, undated or no longer matches the plant.
• A capital project has reached FEED or detailed design and needs an independent chair.
• A safety instrumented function was specified with no documented SIL determination behind it.
• A new substance or change of duty has altered the hazard profile and nobody has reassessed it.

Frequently asked questions

Do we need a HAZOP or a DSEAR assessment?

They answer different questions and most sites need both. A HAZOP examines deviations from design intent across the process. A DSEAR assessment addresses the legal duty around fire and explosion risk from dangerous substances, underpinned by hazardous area classification.

Can you chair a study on a plant you did not design?

Yes, and it is a large part of what we do. An independent chair keeps the discussion disciplined and removes the awkwardness of a designer reviewing their own work. We prepare from your drawings beforehand, so the session is spent on analysis.

How often should hazardous area classification be reviewed?

Whenever the basis changes – a new release source, modified ventilation, a different substance – and as part of periodic process safety review. Classification not maintained under change control stops being a reliable basis for equipment selection.

What happens to the actions after the report?

We record actions with owners and a clear basis, then support close-out: design work, an equipment specification, a SIL verification, or your action review.

Related: our process safety work is one of six areas covered under engineering services. We also work across a range of regulated sectors and industries.

Whether you need one study chaired, assessments brought up to date, or a team to close the actions, we will give you a straight view of what is required. Talk to us about your site. Request a call