"GB/T 21782.4-2008 Powder coatings - Part 4: Calculation of the lower limit of explosion" specifies the calculation method of the lower limit of explosion of powder coatings. The standard is equivalent to ISO 8130-4:1992, which is applicable to the calculation of the minimum concentration of powder coatings dust in the air to form an explosive mixture. The calculation is based on the total calorific value of the product or the total calorific value of each component measured in ISO 1928:1995. This method provides a scientific basis for the security evaluation of the Coating workplace and avoids underestimating the explosion hazard. The standard is centralized by the National Technical Committee for Standardization of Hazardous Chemicals Management. It was issued on May 12, 2008 and implemented on September 1, 2008.