依照IMDG CODE 的规定，危险品分为以下九类:
| CLASS 1 | 爆炸品(Explosives) |
| CLASS 2 | 气体 Gases |
| 2.1 | 易燃气体(Flammable gases) |
| 2.2 | 非易燃性无毒气体(Non-Flammable, Non-Toxic gases) |
| 2.3 | 有毒气体(Toxic gases) |
| CLASS 3 | 易燃液体(Flammable liquids) |
| CLASS 4 | 危险固体 Dangerous solids |
| 4.1 | 易燃固体(Flammable solids) |
| 4.2 | 易自燃物质(Spontaneous combustion substance) |
| 4.3 | 遇水放出易燃气体物质 ( The substance that emit flammable gases when wet water ) |
| CLASS 5 | 5.1-氧化剂(Oxidizing substances) |
| 5.2 | 有机过氧化物(Organic peroxides) |
| CLASS 6 | 6.1-有毒物质(Toxic substances) |
| 6.2 | 感染性物质(Infectious substances) |
| CLASS 7 | 放射性物质(Radioactive material) |
| CLASS 8 | 腐蚀品(Corrosive substances) |
| CLASS 9 | 杂类危险货物(Miscellaneous dangerous substances) |