In accordance with the Major Accidents Ordinance, the competent authority is obliged to determine for the operators of establishments which establishments or groups of establishments, due to their geographical location, their distance from each other and the hazardous substances present in their installations, may have an increased probability of major accidents or which may have more serious consequences (domino effect). For the assessment, the authority uses in particular

• the information provided by the operator in the notification and in the safety report,
• the information provided by the operator following a request for additional information from the competent authority, and
• the information obtained by the competent authority through monitoring measures.

The information to be reported by the operator also includes circumstances in the immediate vicinity of the establishment which could trigger an incident or exacerbate its consequences, e.g. details of neighboring establishments, other establishments not covered by the Major Accidents Ordinance, and areas and developments from which an incident could emanate or where the probability of an incident occurring could increase or the consequences of an incident and domino effects could be exacerbated. If the authority also has additional information, it must make this available to the operator without delay, insofar as this is necessary for cooperation between the operators.