Each substance is assigned a Hazard number, indicating the major hazard associated with it.
| 2. Emission of gas due to pressure of to chemical reaction | |
| 20 | Asphyxiant gas or gas with no subsidiary risk |
| 22 | Refrigerated liquefied gas, asphyxiant |
| 223 | Refrigerated liquefied gas, flammable |
| 225 | Refrigerated liquefied gas, oxidizing (fire-intensifying) |
| 23 | Flammable gas |
| 238 | Gas, flammable corrosive |
| 239 | Flammable gas, which can spontaneously lead to violent reaction |
| 25 | Oxidizing (fire-intensifying) gas |
| 26 | Toxic gas |
| 263 | Toxic gas, flammable |
| 265 | Toxic gas, oxidizing (fire-intensifying) |
| 268 | Toxic gas, corrosive |
| 28 | Gas, corrosive |
| 3. Flammability of liquids (vapours) and gases of self-heating liquid | |
| 30 | Flammable liquid (flash-point between 23 °C and 60 °C, inclusive) or flammable liquid or solid in the molten state with a flash-point above 60 °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 |
| X323 |
Flammable liquid which reacts dangerously with water, emitting flammable gases
This substance will react dangerously with water |
| 33 | Highly flammable liquid (flash-point below 23 °C) |
| 333 | Pyrophoric liquid |
| X333 |
Pyrophoric liquid which reacts dangerously with water
This substance will react dangerously with water |
| 336 | Highly flammable liquid, toxic |
| 338 | Highly flammable liquid, corrosive |
| X338 |
Highly flammable liquid, corrosive, which reacts dangerously with water
This substance will react dangerously with water |
| 339 | Highly flammable liquid which can spontaneously lead to violent reaction |
| 36 | Flammable liquid (flash-point between 23 °C and 60 °C, inclusive), slightly toxic, or self-heating liquid, toxic |
| 362 | Flammable liquid, toxic, which reacts with water, emitting flammable gases |
| X362 |
Flammable liquid toxic, which reacts dangerously with water, emitting flammable gases
This substance will react dangerously with water |
| 368 | Flammable liquid, toxic, corrosive 38 flammable liquid (flash-point between 23 °C and 60 °C, inclusive), slightly corrosive or self-heating liquid, corrosive |
| 382 | Flammable liquid, corrosive, which reacts with water, emitting flammable gases |
| X382 |
Flammable liquid, corrosive, which reacts dangerously with water, emitting flammable gases1 39 flammable liquid, which can spontaneously lead to violent reaction
This substance will react dangerously with water |
| 4. Flammability of solids or self-heating solid | |
| 40 | Flammable solid, or self-reactive substance, or self-heating substance, or polymerizing substance |
| 423 | Solid which reacts with water, emitting flammable gases, or flammable solid which reacts with water, emitting flammable gases or self-heating solid which reacts with water, emitting flammable gases |
| X423 |
Solid which reacts dangerously with water, emitting flammable gases, or flammable solid which reacts dangerously with water, emitting flammable gases, or self-heating solid which reacts dangerously with water, emitting flammable gases
This substance will react dangerously with water |
| 43 | Spontaneously flammable (pyrophoric) solid |
| 44 | Flammable solid, in the molten state at an elevated temperature |
| 446 | Flammable solid, toxic, in the molten state, at an elevated temperature |
| 46 | Flammable or self-heating solid, toxic |
| 462 | Toxic solid which reacts with water, emitting flammable gases |
| X462 |
Solid which reacts dangerously with water, emitting toxic gases
This substance will react dangerously with water |
| 48 | Flammable or self-heating solid, corrosive |
| 482 | Corrosive solid which reacts with water, emitting flammable gases |
| X482 |
Solid which reacts dangerously with water, emitting corrosive gases
This substance will react dangerously with water |
| 5. Oxisizing (fire-intensifying) effect | |
| 50 | Oxidizing (fire-intensifying) substance |
| 539 | Flammable organic peroxide |
| 55 | Strongly oxidizing (fire-intensifying) substance |
| 556 | Strongly oxidizing (fire-intensifying) substance, toxic |
| 558 | Strongly oxidizing (fire-intensifying) substance, corrosive |
| 559 | Strongly oxidizing (fire-intensifying) substance, which can spontaneously lead to violent reaction |
| 56 | Oxidizing substance (fire-intensifying), toxic |
| 568 | Oxidizing substance (fire-intensifying), toxic, corrosive |
| 58 | Oxidizing substance (fire-intensifying), corrosive |
| 59 | Oxidizing substance (fire-intensifying) which can spontaneously lead to violent reaction |
| 6. Toxicity or risk of infection | |
| 60 | Toxic or slightly toxic substance |
| 606 | Infectious substance |
| 623 | Toxic liquid, which reacts with water, emitting flammable gases |
| 63 | Toxic substance, flammable (flash-point between 23 °C and 60 °C, inclusive) |
| 638 | Toxic substance, flammable (flash-point between 23 °C and 60 °C, inclusive), corrosive |
| 639 | Toxic substance, flammable (flash-point not above 60 °C) which can spontaneously lead to violent reaction |
| 64 | Toxic solid, flammable or self-heating |
| 642 | Toxic solid, which reacts with water, emitting flammable gases |
| 65 | Toxic substance, oxidizing (fire-intensifying) |
| 66 | Highly toxic substance |
| 663 | Highly toxic substance, flammable (flash-point not above 60 °C) |
| 664 | Highly toxic solid, flammable or self-heating |
| 665 | Highly toxic substance, oxidizing (fire-intensifying) |
| 668 | Highly toxic substance, corrosive |
| X668 |
Highly toxic substance, corrosive, which reacts dangerously with water
This substance will react dangerously with water |
| 669 | Highly toxic substance which can spontaneously lead to violent reaction |
| 68 | Toxic substance, corrosive |
| 69 | Toxic or slightly toxic substance, which can spontaneously lead to violent reaction |
| 7. Radioactivity | |
| 70 | Radioactive material |
| 768 | Radioactive material, toxic, corrosive |
| 78 | Radioactive material, corrosive |
| 8. Corrosivity | |
| 80 | Corrosive or slightly corrosive substance |
| 80 | Corrosive or slightly corrosive substance, which reacts dangerously with water |
| 823 | Corrosive liquid which reacts with water, emitting flammable gases |
| 83 | Corrosive or slightly corrosive substance, flammable (flash-point between 23 °C and 60 °C, inclusive) |
| X83 |
Corrosive or slightly corrosive substance, flammable, (flash-point between 23 °C and 60 °C, inclusive), which reacts dangerously with water
This substance will react dangerously with water |
| 839 | Corrosive or slightly corrosive substance, flammable (flash-point between 23 °C and 60 °C inclusive) which can spontaneously lead to violent reaction |
| X839 |
Corrosive or slightly corrosive substance, flammable (flash-point between 23 °C and 60 °C inclusive), which can spontaneously lead to violent reaction and which reacts dangerously with water
This substance will react dangerously with water |
| 84 | Corrosive solid, flammable or self-heating |
| 842 | Corrosive solid which reacts with water, emitting flammable gases |
| 85 | Corrosive or slightly corrosive substance, oxidizing (fire-intensifying) |
| 856 | Corrosive or slightly corrosive substance, oxidizing (fire-intensifying) and toxic |
| 86 | Corrosive or slightly corrosive substance, toxic |
| 88 | Highly corrosive substance |
| X88 |
Highly corrosive substance, which reacts dangerously with water
This substance will react dangerously with water |
| 883 | Highly corrosive substance, flammable (flash-point between 23 °C and 60 °C inclusive) |
| 884 | Highly corrosive solid, flammable or self-heating |
| 885 | Highly corrosive substance, oxidizing (fire-intensifying) |
| 886 | Highly corrosive substance, toxic |
| X886 |
Highly corrosive substance, toxic, which reacts dangerously with water
This substance will react dangerously with water |
| 89 | Corrosive or slightly corrosive substance, which can spontaneously lead to violent reaction |
| 9. Risk of spontaneous violent reaction | |
| 90 | Environmentally hazardous substance; miscellaneous dangerous substances |
| 99 | Miscellaneous dangerous substance carried at an elevated temperature. |