These Regulations lay down rules for the prevention of major accidents which involve dangerous substances, and provide the limitation of their consequences for human health and the environment, with a view to ensuring a high level of protection throughout the European Union in a consistent and effective manner. These provisions implement Directive 2012/18/EU on the control of major accident hazards involving dangerous substances. prevention policy. Obligations and duties of operators in control of the operation of an establishment or installation are specified. These obligations include the adoption of a document in writing setting out the major-accident prevention policy (MAPP) and to ensure that it is properly implemented. The MAPP shall be designed to ensure a high level of protection of human health and the environment. It shall be proportionate to the major-accident hazards.