Class 2: Gases

Hazard class 2

Gases can be a pure gas or a mixture of one or more gases. They are defined by dangerous goods regulations as substances which have a vapour pressure greater than 300 kPa (3 bar) at 50°C, or which at a standard pressure of 101 kPa are completely gaseous at 20°C.

Substances and articles of Class 2 have been assigned to one of the following divisions:

Subdivision of gases

Gases are sub-divided into compressed gases, liquefied gases, refrigerated liquefied gases, dissolved gases, aerosol dispensers and receptacles, other articles containing gas under pressure, non-pressurized gases subject to special requirements (gas samples), chemicals under pressure and adsorbed gas.

Except for aerosols and chemicals under pressure, Class 2 gases are divided between the following groups according to their hazardous properties:

 

Reasons for regulation

Gases can pose serious hazards due to their flammability, potential as asphyxiants, ability to oxidize and/or their toxicity or corrosiveness.

Examples of commonly transported explosives

Examples for Class 2 dangerous goods are aerosols, compressed gas, fire extinguishers, refrigerant gases, lighters, acetylene, carbon dioxide, helium, hydrogen, oxygen, nitrogen, natural gas, petroleum gases, liquified, butane, propane, methane, ethylene.