What do Dewar containers primarily hold?

Dewar containers are specifically designed to hold cryogenic liquids, such as liquid nitrogen or liquid helium. These containers utilize a vacuum insulation system to minimize heat transfer, allowing extremely low temperatures to be maintained for the cryogenic liquids inside. The construction and design are essential to preserving the properties of these materials, which can reach temperatures far below freezing.

In contrast, other types of containers are better suited for different substances. For example, while compressed gas can be held in different types of cylinders, they do not typically have the same vacuum insulation as Dewar containers. Similarly, flammable liquids and liquid propane require containers with different characteristics to safely contain and manage their risks. Therefore, the function and structure of a Dewar container uniquely enable it to hold cryogenic liquids effectively.