During the storage, harmful insects can cause serious losses measured on a global scale in bilions. Alternative methods according to the IPM are established also based on the growing public awareness of residues in products and increased contamination rate. Use of inert dust as protection of stored products has physical as well as the possible chemical activities. Its toxicity is negligible, it is safe to use and they do not influence the quality and the value of the product, provides long-term protection. The research objective was the testthe efficiency of non-chemical substances on the economically significant harmful insects in storages. The experiment was performed on the three insects species : Sitophilus oryzae L. – rice weevil, Rhyzopherta dominica Fabricius – lesser grain borer and Tribolium castaneum Herbst – red flour beetle. Two different preparations were used the IPE 1 at the concentration of 0.04g and IPE 2 at the concentration of 0.02 g. The composition formulation IPE 1: Amorphous silicon dioxide (SiO2), laurel (Laurus nobilis L.), sesame seeds (Sesamum indicum L.) and nutrient basis, and IPE 2: amorphous silicid dioxid (SiO2), extract of sesame seeds (Sesamum indicum L.), pyrethrin from dalmatian pyrethrum (Chrysanthemum cinerariaefolium Vis.), and nutritive basis. The effectiveness of the IPE 1 and IPE 2 is different depending on the insect species and the exposure time. According to the average value of mortality, the most sensitive species was, at both preparations, S. oryzae (mortality 100% at IPE 1 and 90.5% at IPE 2 after 21 days of exposure, respectively). It is followed by R. dominica which responded only on IPE 1 (100% mortality), but it was less sensitive on IPE 2 (34.5% mortality). The less sensitive insect was T. castaneum at both preparations (68.5% at IPE 1 and 39.0% at IPE 2 after 21 days of exposure, respectively).