In accordance with the Major Accidents Ordinance, the competent authority is obliged to determine vis-à-vis the operators of establishments which establishments or groups of establishments may be subject to an increased likelihood of major accidents due to their geographical location, their distance from each other and the hazardous substances present in their installations, or where such major accidents may have more severe 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 by the competent authority for additional information, and
• the information obtained by the competent authority through monitoring activities.

The information to be provided by the operator shall also include circumstances in the immediate vicinity of the operating area that may trigger an incident or aggravate its consequences, e.g. details of neighboring operating areas, of other operating sites not covered by the Hazardous Incident Ordinance, and of areas and developments from which an incident could originate or where the probability of the occurrence of an incident may increase or where the effects of an incident and domino effects may aggravate. If the authority has additional information beyond this, it shall make it available to the operator without delay, insofar as this is necessary for the cooperation of the operators.