New one-trip containers are rated and certified for overseas export of cargo for multiple trips. The manufacturers CSC plate on the left container door is good for 5 years from date of manufacture.
Used containers are inspected and surveyed for sea worthiness. They must be structurally sound with a solid undercarriage to meet current IICL criteria.
In addition all markings must be intact and the container must be re-certified for shipping and a decal placed on the door.