The specifications should include the G-force and temperature limits specified by the tape manufacturer. In the context of a DR test you might want more stringent temperature limits to avoid waiting for cold tapes to warm up to room temperature.
I have seen computer equipment shipped with special labels designed to change color if the shipment was subject to out of specification conditions. You might want similar labels for your tape shipments. Depending on your concerns about confidentiality, you might want tamper-evident seals for tape containers. If you are subject to specific legal requirements for data protection, the contract should include an explicit committment from the vendor to conform to those requirements. For example, my employer is a hospital, and all contracts that involve entrusting clinical or billing information to vendors include provisions stating that the vendor will comply with HIPPA requirements. The carrier should have a bonding contract that would compensate you for lost or damaged tapes. We use an outside vendor to transport and store offsite tapes. Our auditors have been getting very fussy about having an auditable documentation trail for each change of physical custody of tapes.
