Objective  To verify the reasonability of diacetone alcohol listed as a flammable liquid in the Catalogue of Hazardous Chemicals(2015 Edition) and List of Dangerous Goods, and further to provide evidence for the hazard re-classification of diacetone alcohol products and the adjustment of related administrative measures.

  Methods  The closed-cup flash point was tested and the uncertainty assessment was done to evaluate the flammability of diacetone alcohol. The impurities of diacetone alcohol products were measured with gas chromatography-mass spectrometry. The closed-cup flash point of simulated diacetone alcohol products with different impurities was tested to evaluate the influence of impurities on the flammability.

  Results  The closed cup flash point test showed U₉₅ of diacetone alcohol was(63.6 ±0.8)℃ and ν_eff was 9.8. These experimental results indicated that diacetone alcohol was probably not a flammable liquid. Simulated product testing indicates that diacetone alcohols with acetone mass fractions < 4%, 4%-9%, and > 10% were classified as flammable liquid category 2, category 3, and category 4, respectively. Acetone was the main reason for the high flammability of diacetone alcohol products.

  Conclusions  The rationality of diacetone alcohol supervised as flammable liquid needs further study. Manufacturers are suggested to reduce the flammable hazard of products by reducing the impurity content.