The safety parameters of the maximum explosion pressure and rate of pressure rise of dispersed flammable dusts are determined under standard conditions in closed apparatus (EN_14034-1, 2011) (ASTM E1226-10, 2010). The values measured vary according to the specific technical parameters of the test apparatus, such as volume, ignition source and dispersion, and according to the inherent dust-specific properties such as chemical composition, combustion heat, surface area etc. For each of four carbonaceous dusts, specifically activated charcoal, polyethylene, lignite and sucrose, 3 to 4 fractions with a number of particle-size distributions were produced and tested in a closed 20 I apparatus under standard conditions. The concentration of carbon dioxide and carbon monoxide and the residual oxygen content in the combustion chamber were determined following each test. The results of these tests were used to determine relationships between the concentration of the dust, the conversion numbers and the released heat of reaction. (C) 2017 Elsevier Ltd. All rights reserved.