1. Member States shall ensure that the competent authority, using the information received from the operators in accordance with Articles 7 and 10, or following a request for additional information from the competent authority, or through inspections pursuant to Article 20, identifies all lower-tier and upper-tier establishments or groups of establishments where the risk or consequences of a major accident may be increased because of the geographical position and the proximity of such establishments, and their inventories of dangerous substances.