P1 to P4: A Practical Way to Rank Ex Inspection Findings

Operational teams often ask how to rank Ex inspection findings once the report lands on the desk. This article sets out a practical four-level priority model (P1 to P4), plus a STOP category for equipment with an unacceptable ignition risk. It then tackles the harder question behind the ranking: an open finding is not automatically unsafe equipment, but it is also not permission to keep running. The difference lies in how findings are classified, justified, assigned, escalated and closed inside the Explosion Protection Document. The realistic operational goal is not zero findings, it is zero uncontrolled Ex failures.

Infographic showing the explosion protection compliance process cycle around an industrial plant, with documentation, inspection, risk management and maintenance.

Operational teams from hazardous-area industries often ask me practical questions about Ex compliance. Let me share one:
“How should we prioritize Ex inspection findings?”

A practical risk-based model could be:

🔴 P1 – Immediate
Ex integrity cannot be demonstrated / credible ignition risk.
Examples: damaged Ex d flamepath, missing critical bolts, failed Ex p pressurisation, unsuitable EPL.
→ Make safe immediately.

🟠 P2 – ≤1 week
Significant degradation, but competent assessment confirms temporary operation is acceptable.
Examples: deteriorating sealing, significant corrosion, gland/bonding deficiencies.

🟡 P3 – ≤1 month
Correction required, but the Ex protection is not presently compromised.
Examples: minor corrosion, deteriorating cable support, minor enclosure damage.

🟢 P4 – Next shutdown
Minor finding not affecting the present explosion-safety function.
Examples: cosmetic corrosion, minor identification/documentation issues.

I would actually add one category above P1:
⛔ STOP / UNSAFE FOR SERVICE

If there is an unacceptable ignition risk, a P1 work order is not enough. The equipment must first be made safe.

Then comes the difficult question:
“The authority says no Ex failures are allowed. We have open findings. As Operational Head, am I on the safe side?”

This is where terminology matters.

Finding ≠ automatically unsafe equipment.
But equally:
Finding ≠ permission to continue operating.

Equipment ages. Installations deteriorate. IEC 60079-17 inspection helps us identify these conditions before they become unacceptable risks.

The important question is therefore not only whether findings exist, but how they are managed.

This is where the EPD becomes powerful:
Inspection → Finding → Classification → Risk assessment → Operational decision → Corrective action → Verification → Closure → Lifetime record

One critical rule:
A corrective-action deadline is the maximum permitted closure period — NOT automatic permission for continued operation.

Imagine an authority sees 37 open findings.

There is a major difference between 37 uncontrolled deficiencies and 37 findings where:
→ critical conditions have already been made safe
→ P2/P3 actions are within justified deadlines
→ P4 items are planned
→ responsibilities are assigned
→ overdue actions are escalated
→ repairs and closure are documented

That is controlled Ex integrity management.

But simply putting P1–P4 into the EPD is not a liability shield.

EPD + justified process + competent decisions + records + actual execution = a much stronger position.

While:
EPD + known findings + missed deadlines + no action = potentially the opposite.

So perhaps the operational objective should not be pretending we can always achieve:
ZERO FINDINGS.

It should be:
ZERO UNCONTROLLED Ex FAILURES.

That, for me, is the foundation of an operational Ex management system.

P1 to P4: A Practical Way to Rank Ex Inspection Findings

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