ISO 8130-4:1992

The lower explosion limit is the minimum concentration of the coating powder in air which will form an explosive mixture. The method is based on the knowledge of the gross calorific value of the product, as determined by the method described in ISO 1928, or on the gross calorific values of the constituents of the product. With powders that are not flammable the method may nevertheless give a value for the lower explosion limit in air.