Objective  To study on the hazards classification method of azodicarbonamide products in transportation, and thus to provide reference for the safe transportation of this type of substances.

  Methods  According to the Recommendations on the Transport of Dangerous Goods and Recommendations on the Transport of Dangerous Goods Manual of Tests and Criteria published by United Nations, 4 kinds of azodicarbonamide products(sample A contains 25% azodicarbonamide and 75% sodium bicarbonate, sample B contains 33.3% azodicarbonamide and 66.7% polyethylene, sample C contains 40% azodicarbonamide and 60% polyethylene, and sample D contains 50% azodicarbonamide and 50% sodium bicarbonate) were subjected to appropriate self-heating test, and heat accumulation storage test was conducted to determine their transportation hazards.

  Results  The test results indicated that sample A can be transported as unrestricted goods; sample B can be transported as unrestricted goods when it is transported in packages less than 3 m³. However, when the package exceeding 3 m3, sample B belongs to self-heating substance and needs to be classified into UN3088. Sample C and D were classified as substances related to self-reactive substances. In addition, sample C also had a secondary risk of self-heating.

  Conclusions  When azodicarbonamide does not exceed 35% of mass content, there is no need to consider the self-reactive hazards, while the product may be self-heating; when azodicarbonamide is greater than 35% of mass content, the product may be both self-reactive and self-heating.