HAZMAT Class 2 Gases

According to the DGR, a gas is defined as "a substance which at 50° C (122° F) has a vapor pressure greater than 300 kPa (3.0 bar) or is completely gaseous at 20° C (68° F) at a standard pressure of 101.3 kPa (1.01 bar)."

There are five physical states of gas, described as follows when packaged under pressure for transport:

• Compressed gas is entirely gaseous at -50° C (-58° F).
• Liquefied gas is partially liquid at temperatures above -50° C (-58° F).
• Refrigerated liquefied gas is made partially liquid because of its low temperature. This is also referred to as cryogenic liquid.
• Dissolved gas is dissolved in a liquid phase solvent.
• Absorbed gas is absorbed into a solid, porous material that results in an internal receptacle pressure of less than 101.3 kPa at 20°C (68° F) and less than 300 kPa at 50°C (122° F).

To learn more about IATA DGR visit our IATA DGR Refresher Online Training web page.