Abstract
This study investigated the disinfection efficacy of slightly acidic hypochlorous acid water（SAHW）for disinfecting baby bottles. The bactericidal effects of SAHW and conventional disinfection methods（boiling, microwave heating, and chemical disinfectants）were compared using Escherichia coli and general viable bacteria as indicators. To simulate post-feeding contamination, baby bottles were filled with milk and inoculated with E. coli, after which the contents were discarded and the bottles were washed under standardized conditions. Ten experimental groups were established: three conventional disinfection groups（boiling, microwave heating, and chemical treatment）, four SAHW groups（1 mL, 5 mL, 10 mL, and 100 mL）, a detergent-only group, a positive control（no washing or disinfection）, and a negative control. After treatment, residual contamination was assessed by culturing rinsates on deoxycholate agar medium and standard nutrient agar medium, and the number of colonies and contamination presence were recorded. All SAHW-treated groups exhibited bactericidal effects against E. coli and general viable bacteria, comparable to those of conventional disinfection methods. These findings suggest the potential applicability of slightly SAHW as a new method for disinfecting baby bottles.
