Microbiostatic effect of indoor air quality management with low-concentration gaseous chlorine dioxide on fungal growth

Abstract Biological contamination of fresh produce by fungi in storage is becoming a serious problem. Gaseous chlorine dioxide (ClO 2 ) has been used to prevent fungal growth on fresh produce; however, the specific effects of gaseous ClO 2 at concentrations low enough to be safe for the human body on fungal growth remain unknown. Therefore, in this study, we aimed to investigate the effect of low-concentration gaseous ClO 2 on fungal growth in sweet potatoes over 1 month. Here, a mechanochemical reaction involving the collision of two types of powders was used to produce low concentrations of gaseous ClO 2 . The experiment was conducted in a container and chlorine dioxide gas was diffused by a circulator to verify its microbiostatic effect in a large space. A clear microbiostatic effect was observed in potatoes without skin when exposed to low-concentration ClO 2 for 3 days. Notably, low concentrations (< 1.0 ppm) of ClO 2 reduced Rhizopus stolonifer growth in sweet potatoes with skin over 1 month. Therefore, low concentrations of gaseous ClO 2 are sufficient to inhibit fungal growth via gas diffusion.