Which label denotes material that must remain frozen?

The label that designates material that must remain frozen is the DD Form 1502. This form is specifically used in the transportation of perishables, including frozen goods, meeting the strict requirements for handling and transporting items that need to maintain specific temperature conditions to ensure safety and integrity.

In the context of air freight and logistics, it is critical to ensure that items requiring specific temperature control are properly labeled to avoid spoilage and ensure compliance with safety regulations. The DD Form 1502 provides the necessary information for personnel handling the shipment, indicating how the material should be treated during transit.

The other forms listed serve different purposes in military logistics. For instance, the DD Form 1387 is primarily used for marking shipping containers, while the DD Form 250 serves as a receiving report. The DD Form 1450 pertains to a different type of documentation that is not related to temperature-sensitive materials. Therefore, recognizing the specific role of each form is essential for proper material handling in air freight.