1What is a safety report?
L'safety report is the main regulatory document for sites classified as SEVESO (seuil bas/haut) et de nombreuses ICPE subject to authorisation. It follows the PHA structure (hazard → event → consequence) but uses terminology and requirements specific to French regulations: initiating event, top event, hazardous phenomenon, with probability assessed using the regulatory PIGC (Probability, Intensity, Severity, Kinetics) scale.
Unlike general-purpose PHA, probability in a safety report is not rated freely: it uses fixed probability classes (PIGC scale), a condition for the authorities to accept the file.
2Method steps
- Identify the system and its hazard (hazardous substance, stored energy, etc.).
- Describe the initiating event — the failure or error that starts the accident sequence.
- Characterise the top event — the resulting loss of containment or control.
- Describe the hazardous phenomenon that follows (fire, explosion, toxic release, etc.) and its potential consequences.
- Rate severity and probability using the PIGC regulatory scale (fixed, non-editable classes).
- List the risk-control measures — passives (containment, separation distance) and actives (detection, automatic extinguishing)—then position the scenario in the regulatory risk matrix (MMR cells).
Clearly distinguish a passive measure (works without action, e.g. a firewall) from an active measure (requires detection and action, e.g. automatic extinguishing): their expected reliability and justification differ.
3Example completed in Polyodos
Section to be completed — step-by-step example (e.g. loss of containment from flammable-product storage), with Polyodos screenshots and positioning in the PIGC matrix.
4Common mistakes
| Mistake | Why it is a problem |
|---|---|
| Customising the PIGC scale | This regulatory scale is fixed. Changing it within a study removes the file's comparability and may lead the authorities to reject it. |
| Confusing the top event with the hazardous phenomenon | The top event is the loss of containment or control; the hazardous phenomenon is what follows (fire, explosion). One leads to the other, and they are not interchangeable. |
| Using only one risk-control measure per line of defence | A single barrier, even a reliable one, is generally insufficient to justify lowering the probability class. Defence in depth, with several independent measures, is expected. |