Class 2 - Gases
2.1 Flammable gases
2.2 Non-flammable, non-toxic gases
2.3 Toxic gases
The heading of Class 2 covers pure gases, mixtures of gases, mixtures of one or more gases with one or more other substances and articles containing such substances.
A gas is a substance which:
- at 50 °C has a vapour pressure greater than 300 kPa (3 bar); or
- is completely gaseous at 20 °C at the standard pressure of 101.3 kPa.
Sub-classifications
The substances and articles of Class 2 are subdivided as follows:| 1 | Compressed gas: a gas which when packaged under pressure for carriage is entirely gaseous at -50 °C; this category includes all gases with a critical temperature less than or equal to -50 °C |
|---|---|
| 2 |
Liquefied gas: a gas which when packaged under pressure for carriage is partially liquid at temperatures above -50 °C. A distinction is made between:
|
| 3 | Refrigerated liquefied gas: a gas which when packaged for carriage is made partially liquid because of its low temperature |
| 4 | Dissolved gas: a gas which when packaged under pressure for carriage is dissolved in a liquid phase solvent |
| 5 | Aerosol dispensers and receptacles, small, containing gas (gas cartridges) |
| 6 | Other articles containing gas under pressure |
| 7 | Non-pressurized gases subject to special requirements (gas samples) |
| 8 | Chemicals under pressure: liquids, pastes or powders, pressurized with a propellant that meets the definition of a compressed or liquefied gas and mixtures thereof |
| 9 | Absorbed gas: a gas which when packaged for carriage is adsorbed onto a solid porous material resulting in an internal receptacle pressure of less than 101.3 kPa at 20 °C and less than 300 kPa at 50 °C. |
Groups
Substances and articles (except aerosols and chemicals under pressure) of Class 2 are assigned to one of the following groups according to their hazardous properties, as follows:| A | asphyxiant |
|---|---|
| C | corrosive |
| O | oxidizing |
| F | flammable |
| T | toxic |
| TF | toxic, flammable |
| TC | toxic, corrosive |
| TO | toxic, oxidizing |
| TFC | toxic, flammable, corrosive |
| TOC | toxic, oxidizing, corrosive |