第1类：爆炸品
第2类：气体
第3类：易燃液体
第4类：易燃固体；易于自燃的物质；遇水放出易燃气体的物质
第5类：氧化性物质和有机过氧化物
第6类：毒性物质和感染性物质
第7类：放射性物质
第8类：腐蚀性物质
第9类：杂项危险品
According to United Nations < Recommendations on the Transport of Dangerous Goods >, dangerous goods are divided into nine hazard classes as follows:
Class 1, Explosives
Class 2, Gases
Class 3, Flammable Liquids
Class 4, Flammable Solids; Substances Liable to Spontaneous Combustion; Substances Which, in Contact with Water, Emit Flammable Gases
Class 5, Oxidizing Substances and Organic Peroxides
Class 6, Toxic and Infectious Substances
Class 7, Radioactive Material
Class 8, Corrosives
Class 9, Miscellaneous Dangerous Goods