The safety characteristics p(max) and K-St of a flammable dust are usually determined in a closed apparatus (20 l- or 1 m(3)-vessel). The results are strongly influenced by the parameters of the apparatus (e.g. the volume, geometry, dispersion system). The aim of this project is to investigate whether there is a correlation between p(max) and K-St on the one hand and the calorific value H-S and the specific surface area S-m of the dust on the other. In an experimental study, around 200 dust samples from different sectors of industry will be analysed. The analysis of around 102 dusts shows that the correlation may be described by a logarithmic function. Owing to differences in reaction mechanism it is reasonable to formulate different functions for different substance groups (e.g. metals, organic materials). This may lead to an algorithm which can predict p(max) and K-St from H-S and S-m within a defined range of error. (C) 2015 Elsevier Ltd. All rights reserved.