Limestone powder popularly used as an anti-explosive agent in the mining industry and as an absorbent for exhaust fume desulphurization in the energy industry, both of which take advantage of the powder’s, favourable flow properties. In this project, evaluations of the influence of commercial modifiers on the flow properties of hydrophobized limestone powders were measured. The analysis was carried out on the basis of densimetric measurements with the use of a powder characteristics tester. It was stated that the hydrophobization process improves not only the waterproof properties of limestone powders, but also reduces cohesion and improves flow properties.