Safety of Concentrated Bioshell Calcium Oxide Water Application for Surface and Skin Disinfections against Pathogenic Microbes

Immediately post-production, commercially available bioshell calcium oxide (BiSCaO) water is colorless, transparent, and strongly alkaline (pH 12.8), and is known to possess deodorizing properties and broad microbicidal activity. However, BiSCaO Water may represent a serious safety risk to the living body, given the strong alkalinity. This study aimed to investigate the safety of BiSCaO Water for use as an antiseptic/disinfectant despite concerns regarding its high alkalinity. The change over time in pH of BiSCaO Water was measured during air contact (stirring BiSCaO Water in ambient air). When sprayed on metal, plastic, wood piece, paper, and skin surfaces, the pH of BiSCaO Water decreased rapidly, providing a white powder coating upon drying. Scanning electron microscopy images, energy dispersive X-ray elemental mapping, and X-ray diffractograms showed that the dried powder residues of BiSCaO Water were composed primarily of calcium carbonate. These results suggested that BiSCaO Water is a potent reagent that may overcome the obstacles of being strongly alkaline, making this material appropriate for use in disinfection against pathogenic microbes.