2.5 Update of an Approved Safety Case The safety case is a working document that must be maintained up-to-date by the petroleum undertaking such that all parts of it accurately reflect the actual conditions in carrying out designated petroleum activities under a safety permit. Where a proposed alteration to the manner in which a designated petroleum activity is carried on is a material change, the petroleum undertaking cannot make that alteration until a safety case with the proposed alteration has been submitted and approved by the CER and the relevant safety permit reissued. Material changes to safety cases will be assessed by the CER in accordance with its Safety Permit Application Guidelines.