A chlorine-free drain cleaner is a product designed to clean and clear clogged household pipes. Its main feature is that it does not use chlorine-based compounds, such as sodium hypochlorite, to dissolve debris. Instead, its effectiveness is based on other substances. These are often strong bases, such as sodium hydroxide or "lye," which chemically react with organic materials like fats, hair, food scraps, or soap and break them down. Another variation includes cleaners based on enzymes and bacteria that gradually biologically digest organic matter. Due to the absence of chlorine, this type of cleaner is suitable for use in households connected to a septic tank or a domestic wastewater treatment plant (WWTP), as it does not kill the beneficial bacteria necessary for their proper function. It also does not cause the characteristic pungent odor associated with chlorine disinfectants and is gentler on certain types of pipes.