Since the application of AB0.2 resulted in the greatest efficacy towards the tested dicotyledonous plant, it was also necessary to analyse its potential threat to non-target organisms. It is assumed that only 5% of active substances of herbicide formulations interact with target organisms, while the remaining 95% affects non-target organisms or penetrates the environment, either accumulating in the soil or leaching into groundwater. In addition, it is well known that cationic surfactants exhibit very high toxicity to aquatic organisms. For example, benzalkonium chloride, popularly used as an active ingredient in disinfectant formulations, exhibits very high acute toxicity to freshwater crustaceans (Daphnia magna, EC50 = 0.016 mg dm -3 ), algae (Chlorella vulgaris, EC50 up to 0.0576 mg dm -3 ) or fish (Oncorhynchus mykiss, gill cell line-W1, EC50 = 0.31 mg dm -3 ). To provide a preliminary evaluation of the risks associated with obtaining ILs and DSILs with a surface-active amphiphilic cation, an acute toxicity analysis was performed using a model organism from the freshwater algae group, C. vulgaris. The study was performed for both parent ILs, A and B, as well as DSIL AB0.2. Based on the analysis of the obtained dose-response (BAC16, EC50: 0.16 mg dm -3 ). This type of activity also indicates additional potential for the use of AB0.2 as an algicide (e.g., to counteract algal growth in pools or ponds) at welldefined concentrations. Algicides are also used to counteract the eutrophication in natural water bodies. One of the most commonly used substances to counteract algal growth is copper(II) sulfate, however, this compound exhibits considerable toxicity to other aquatic organisms.