Evaluating the Influence of Environmental Factors on the Stability of Commercial Chlorine-Based Sanitizers Using Response Surface Modeling

Given the increasing use of chlorine-based disinfectants and concerns regarding their shelflife and persistence on the surface, the present study investigated the effect of environmental conditions on the stability of commercial solutions stored under different conditions. This study assessed the stability of ۰.۰۵%, ۰.۵%, and ۱% sodium hypochlorite solutions at pH levels of ۵, ۷.۵, and ۱۰ stored at temperatures of ۴ ° C, ۲۵ ° C, and ۴۵ ° C using iodometric titration at ۰, ۱۵, ۳۰, and ۶۰ days after preparation. Eighty-seven solutions from three commercial brands (Brand A, Brand B, and Brand C) were prepared based on experimental design and response surface modeling (RSM) using Box-Behnken factorial design (BBD). The results revealed that the linear coefficient effects of all factors (temperature, storage time, pH, and initial concentration) were statistically significant (P<۰.۰۵). However, no significant differences were found among the three commercial brands (P=۰.۳۰۷). A negative correlation was observed between free available chlorine (FAC) and storage time. Solutions with a higher initial concentration (۱%) tended to have lower stability. Higher temperatures also contributed to the instability of the solutions. Moreover, a gradual decrease was observed in the pH over time, and the lowest stability was detected at a neutral pH of ۷.۵. These findings suggest that environmental conditions (e.g., temperature, storage duration, pH, and initial concentration) significantly affect the stability of chlorine in the solutions. Therefore, these factors should be considered when using chlorine and storing chlorine-based disinfectants (CBDs) to ensure optimal performance and effectiveness.