The British Committee for Standards in Haematology guidelines state that blood must be stored only in blood transfusion refrigerators, and not in ward or domestic refrigerators. It should be stored or transported in boxes designated for this purpose and which have been verified as satisfactory for transporting blood, including the time for which storage is satisfactory. It is a good practice for hospital blood banks to record the time when blood was placed into a box, the time for which storage will be satisfactory and to indicate that blood should be returned to a blood transfusion refrigerator if it is not used within that time. The transfusion of blood and blood components should begin as soon as possible after delivery to the ward or operating theatre. If this is not possible, it should be returned to a blood transfusion refrigerator with the time of return documented. If a unit of blood has been out of the refrigerator for more than 30 min and there is no prospect of its imminent transfusion, the hospital blood bank should be informed that it has been un-refrigerated for more than 30 min, and the blood returned to the hospital blood bank for disposal because of the risk of bacterial growth.