|
|
|
|
|
|
|
|
This system is employed in continental Europe as a placarding system for vehicles. It gives a quick appreciation of the degree and type of hazard which might be encountered in the event of an incident.
The hazard identification number consists of two or three figures. In general the figures indicate the following hazards:
| 2 | Emission of gas due to pressure or to chemical reaction |
| 3 | Flammability of Liquids (vapours) and gases or self heating liquid |
| 4 | Flammability of solids or self heating solid |
| 5 | Oxidising (fire intensifying) effect |
| 6 | Toxicity or risk of infection |
| 7 | Radioactivity |
| 8 | Corrosivity |
| 9 | Risk of spontaneous violent reaction |
NOTE The risk of spontaneous violent chemical reaction includes the possibility following from the nature of a substance of a risk of explosion, disintegration and polymerisation reaction following the release of considerable heat or flammable and/or toxic gases,
Doubling, of a figure indicates an intensification of that particular hazard.
Where the hazard associated with a substance can be adequately indicated by a single figure, this is followed by Zero
Combinations of figures gives a special meaning 22, 323. 333, 362, 382, 423 44, 446, 462, 482, 539, 606, 623, 642, 823, 842 and 90 (see below)
If a hazard identification number is prefixed by the letter "X", this indicates that the substance will react dangerously with water. For such substances, water may only be used by approval of experts.
For example the hazard identification numbers listed below have the foIIowing meanings:
| 20 | Asphyxiant gas or gas with no subsidiary risk |
| 22 | Refrigerated liquefied gas, asphyxiant. |
| 223 | Refrigerated liquefied gas, flammable |
| 225 | Refrigerated liquefied gas, oxidising (fire-intensifying.) |
| 23 | Flammable gas |
| 239 | Flammable gas which can spontaneously lead to violent reaction |
| 25 | Oxidising (fire-intensifying) gas. |
| 26 | Toxic gas |
| 263 | Toxic gas, flammable |
| 265 | Toxic gas, oxidising (fire-intensifying) |
| 268 | Toxic gas, corrosive |
| 30 | Flammable liquid (flash-point between 23' and 61 'C inclusive) or flammable liquid or solid in the molten state with a flash-point above 61 'C heated to a temperature equal to or above its flash-point. or self-heating liquid. |
| 323 | Flammable liquid which reacts with water emitting flammable gases |
| X232 | Flammable liquid which reacts dangerously with water, emitting flammable gases. |
Kemler codes have been allocated for all the items in the United Nations number list.
