Verify that the vehicle complies with ATP (Agreement on the International Carriage of Perishable Foodstuffs) standards, which categorize vehicles by their cooling efficiency (e.g., Class FRC for -20°C). For the vehicle itself, ensure it meets Euro IV, V, or VI emission standards depending on your local regulations. Request ISO 9001 for manufacturing quality and CE certification for the refrigeration components. If importing to the US or EU, check for DOT or WVTA (Whole Vehicle Type Approval) documentation.