What is meant by ‘initiating event’ in LOPA?

In Layer of Protection Analysis (LOPA), the term ‘initiating event’ refers to an event or occurrence that sets off a sequence leading to a hazardous situation or incident. This concept is crucial in risk analysis because identifying initiating events helps in understanding how risks can materialize and lead to unwanted consequences. By knowing what events could trigger a potential hazard, organizations can better design protection layers to mitigate these risks.

The first choice accurately captures this definition, emphasizing the causal relationship between the initiating event and the resulting hazardous situation. In the context of LOPA, identifying such initiating events is a fundamental step in assessing the adequacy of existing safeguards and determining any additional protective layers needed.

In contrast, the other choices do not align with the definition of an initiating event. A preventive measure relates to strategies put in place to stop risks from occurring in the first place rather than describing a triggering event. An evaluation of potential impacts focuses on the consequences of a risk event rather than the event itself. Lastly, a report of past incidents pertains to previous occurrences rather than defining a new triggering event leading to hazards. Thus, the first choice is the most accurate representation of what an initiating event is within the framework of LOPA.