What is required when transporting materials classified as "Cryogenic Liquids"?

When transporting materials classified as "Cryogenic Liquids," proper insulation and pressure relief devices are essential for ensuring safety and maintaining the integrity of the materials. Cryogenic liquids are extremely low-temperature substances, often requiring specialized equipment to prevent their rapid vaporization and expansion, which can lead to dangerous pressures if not managed correctly.

Insulation is crucial because it helps maintain the low temperatures necessary to keep these materials in their liquid state. Without adequate insulation, heat would transfer into the container, causing the liquid to boil off and create gas, significantly increasing pressure.

Pressure relief devices are equally important as they prevent a dangerous buildup of pressure inside the container. If the pressure becomes too high due to vaporization, it could lead to catastrophic failure of the container, posing serious risks to safety and property.

Therefore, the combination of proper insulation and pressure relief mechanisms is vital for the safe transportation of cryogenic liquids, making this the accurate requirement. Other options, while they may have their importance in different contexts, do not fully address the specific needs associated with transporting cryogenic materials.