Bactericidal activities of selected organic N-halamines

The bactericidal efficacies of three organic N,N'-dihalamine disinfectants in the class of compounds termed imidazolidinones were determined for combinations of pH, temperature, and water quality treatments by using Staphylococcus aureus and Shigella boydii as test organisms. The compound 1,3-dibromo-4,4,5,5-tetramethyl-2-imidazolidinone was found to be the most rapidly acting bactericide, especially under halogen-demand-free conditions. The mixed N,N'-dihalamine 1-bromo-3-chloro-4,4,5,5-tetramethyl-2-imidazolidinone was found to be intermediate in terms of rate of disinfection, while the compound 1,3-dichloro-4,4,5,5-tetramethyl-2-imidazolidinone was observed to be the slowest acting bactericide. When overall effectiveness was judged on the basis of stability of the disinfectants along with rates of disinfection, the mixed halamine was considered to exhibit great potential for use as a disinfectant in an aqueous solution.