6. Member States shall ensure that internal and external emergency plans are reviewed, tested, and where necessary updated by the operators and designated authorities respectively at suitable intervals of no longer than three years. The review shall take into account changes occurring in the establishments concerned or within the emergency services concerned, new technical knowledge, and knowledge concerning the response to major accidents.
With regard to external emergency plans, Member States shall take into account the need to facilitate enhanced cooperation in civil protection assistance in major emergencies.