Stage 1 — immediate notification
As soon as the event occurs, the following are notified:
- place, date and time of the accident,
- a short description of the event,
- the dangerous substances involved and estimated quantities,
- the first identified effects on human health and the environment,
- the emergency measures taken.
The purpose of the first notification is not to be complete but to be fast: getting the outside response right depends on it.
Stage 2 — the detailed report
Afterwards, the causes and development of the accident, a detailed assessment of its consequences, the measures taken and the measures to be taken to prevent recurrence are reported. This report is not a defence document; it is where the lesson gets recorded.
When information arrives later
As the investigation deepens the first assessment can change: what was thought to be the cause turns out to be a symptom, the affected area widens. When new information emerges the report is updated. Withholding new information to defend what the first report said is the most expensive mistake available in this field.
Near misses
Events below the notification threshold still enter the establishment's own system. Almost every major accident was preceded by smaller versions of the same chain; the near-miss record is that chain's free warning.
Relation to the internal investigation
The notification made outward does not replace the root cause analysis carried out inside. The two run and are written separately; the systemic weaknesses found internally become inputs to the safety management system and the scenario document.