1. Notwithstanding the deadline set out in Article 6(3), second subparagraph, Member States shall ensure that critical entities carry out a risk assessment within nine months of receiving the notification referred to in Article 6(3), whenever necessary subsequently, and at least every four years, on the basis of Member State risk assessments and other relevant sources of information, in order to assess all relevant risks that could disrupt the provision of their essential services ('critical entityrisk assessment').