Class 2 Gases are defined as what?

• A. Gases are liquids at room temperature
• B. Gases are under pressure in a container
• C. Gases are mixtures under pressure in a container
• D. Gases are solids

Answer: (C)

Gases in Class 2 are defined by being stored under pressure in a container. The key idea is that the hazardous material class centers on how the gas is kept and transported—in a sealed vessel under pressure—rather than its physical state at room temperature. In practice, the contents of these cylinders are often blends or mixtures of different gas components chosen for specific applications, which is why describing Class 2 gases as mixtures under pressure in a container fits the common reality of their storage and use. The other statements don’t fit because gases are not liquids or solids at typical room temperatures, and the essential feature highlighted here is the pressurized containment (often with a mixture) rather than any other state characteristic.