Quaternary ammonium compounds (QACs) are one of the the most effective classes of antimicrobial agents that have been used over the past century. Their high efficiency is based on the presence of a positively charged nitrogen atom, which allows binding to the negatively charged membranes of microorganisms. Upon binding, long hydrocarbon chains attached to the nitrogen atom destabilize the membranes of the microorganisms, leading to their destruction. The hydrocarbon chains enables significant structural diversity within this group od compounds, while the simplicity of their synthesis enables high production and wide application in everyday life and various industrial sectors. The most commonly used QACs are benzalkonium chloride (BAC), cetyltrimethylammonium bromide (CTAB), didecyldimethylammonium chloride (DDAC), and miramistin. Due to their stability and good solubility in water, QACs tend to accumulate in wastewater and terrestrial waters, which can have negative consequences for the environment, ecosystems, and human health. These compunds are distinguished by their remarkable biological activity, including antibacterial, antiviral, and antifungal properties, and are also used as herbicides and perticides.