Abstract
Over the past three decades a growing awareness of environmental protection prompted the development of so-called green and sustainable technologies. Therefore, academic and wider community intensively explores new chemicals and safer, more energy efficient processes based on a rational compromise between economic, social, and environmental requirements. Due to low volatility and stability, ionic liquids emerged as a potential replacement for traditional volatile and harmful organic solvents. Various studies have been carried out to validate the green character of ionic liquids, whereby data published suggest that these compounds, due to their relatively high toxicity and poor biodegradability, could have an extremely negative impact on the environment. This paper presents the current knowledge on the toxicity of ionic liquids, with a special emphasis on the mechanisms by which this group of compounds causes changes in the morphology and physiology of organisms at different organisational levels of the ecosystem.