Quaternary ammonium compounds are active against vegetative bacteria and nonlipid containing viruses but not against bacterial spores at the usual concentrations (1:750). These compounds are often used as mixtures and in combination with other germicides. However, the activity of quaternary ammonium compounds may be neutralized by organic matter, water hardness and anionic detergents (soap).
Note: Potentially harmful bacteria can grow in quaternary ammonium compound solutions. Also, these compounds may accumulate in the environment as a result of low biodegradability.