Two species of plantsdicotyledonous (white mustard, Sinapis alba) and monocotyledonous (sorghum, Sorghum bicolor) were used as test organisms. The designated wells in plastic containers were filled with 90 cm 3 of certified, OECD-compliant dry soil (MicroBioTests, Belgium) and then the soil was saturated with 25 cm -3 of aqueous solution of the analyzed compounds. Two concentrations of test solutions were selected: 1 g dm -3 and 10 g dm -3 . For the compounds insoluble in water at 10 g dm -3 only the test at 1 g dm -3 was performed, and in the case of 1-dodecylquininium bromide, which was insoluble in water at 1 g dm -3 , the experiment was performed using test solutions with lower concentration (0.1 g dm -3 ). Pure deionized water was used to saturate the soil in the control sample. Subsequently, a sheet of absorbent paper was placed on the saturated soil, and 10 seeds of the selected plant were placed with 1-cm spaces in a single row. Samples were incubated in vertical position, at 26 ±1 °C for 96 hours and the number of germinating seeds in each sample was checked every 24 hours. After the end of the experiment, photos showing plant development were taken and length of roots and shoots of the young plants was measured using ImageJ software. The average growth of the root and stem was calculated in relation to the results recorded for the control sample.