Journal of Mazandaran University of Medical Sciences (Nov 2023)
Investigation the Effect of Environmental Factors on the Sodium Hypochlorite Solution Stability as Disinfection of Environmental Surfaces
Abstract
Background and purpose: Considering that chlorine disinfectants are one of the most common disinfectants for disinfecting water and wastewater, hospital environments, etc., and there are questions about the stability of chlorine in solutions and on surfaces. So, the purpose of this study is to investigate the effect of environmental factors on the stability of sodium hypochlorite solutions stored in different conditions. Materials and methods: In this study, sodium hypochlorite solution was used for solution preparation. According to the number of parameters and based on the design of the experiment (DoE) and the response surface modeling (RSM) using the Box-Benken design (BBD), 29 experiments were performed. The solutions were stored in opaque plastic bottles covered with aluminum foil. The stability of solution in concentration of 0.05, 0.5 and 1% with the pHs of 5, 7.5 and 10 stored at 4, 25 and at 45°C, and the storage time of 15, 30, and 60 days was examined. The residual chlorine concentration was determined by the iodometric method according to the standard method. Results: The results of this study showed that the chlorine stability decreases with increasing concentration of chlorine solution, increasing temperature and storage time. Solutions with neutral pH (7.5) showed less stability than acidic and alkaline solutions. Based on the experimental design and RSM using BBD, the linear effect of the temperature, pH, initial concentration and time was significant (P<0.05). There was a negative correlation between the amount of available chlorine and time. Conclusion: This study showed that different storage conditions of sodium hypochlorite solution strongly affect the stability of its chlorine, so it is recommended to pay attention to these factors when using this solution for disinfection.
