In the case of young sorghum plants, the addition of quinine hydrochloride or quinine-based QASs at a concentration of 10 g dm -3 or lower did not cause statistically significant changes in root or shoot length compared to the control. Thus, no phytotoxic effect of the obtained compounds was observed toward sorghum. Since growth inhibition was not observed at a statistically significant level for white mustard either, it can be concluded that application of the obtained QASs on the stored grain for pest protection will not cause phytotoxic effects. Proteinogenic amino acids are relatively harmless to many groups of aquatic organisms, and their exogenous addition can have beneficial effects on algal growth. Among other things, positive effects of amino acid addition have been observed on the increase in biomass of freshwater algal cultures of C. vulgaris . On the other hand, surface-active QASs containing long alkyl substituents are characterized by high toxicity to aquatic organisms, including microalgae . This is due to the same mechanism of interaction with cell membranes, which is responsible for the antibacterial activity of these compounds , as well as adverse interactions with organelles, including chloroplasts . Given the important role of algae as an essential source of food and oxygen in aquatic biocoenoses, assessing toxicity of new chemicals to this group of organisms is important in the course of the environmental risk analysis. According to the studies we performed on C.