依照IMDG CODE 的規定，危險品分為以下九類:
| CLASS 1 | 爆炸品(Explosives) |
| CLASS 2 | 氣體 Gases |
| 2.1 | 易燃氣體(Flammable gases) |
| 2.2 | 非易燃性無毒氣體(Non-Flammable, Non-Toxic gases) |
| 2.3 | 有毒氣體(Toxic gases) |
| CLASS 3 | 易燃液體(Flammable liquids) |
| CLASS 4 | 危險固體 Dangerous solids |
| 4.1 | 易燃固體(Flammable solids) |
| 4.2 | 易自燃物質(Spontaneous combustion substance) |
| 4.3 | 遇水放出易燃氣體物質 ( The substance that emit flammable gases when wet water ) |
| CLASS 5 | 5.1-氧化劑(Oxidizing substances) |
| 5.2 | 有機過氧化物(Organic peroxides) |
| CLASS 6 | 6.1-有毒物質(Toxic substances) |
| 6.2 | 感染性物質(Infectious substances) |
| CLASS 7 | 放射性物質(Radioactive material) |
| CLASS 8 | 腐蝕品(Corrosive substances) |
| CLASS 9 | 雜類危險貨物(Miscellaneous dangerous substances) |