極低濃度二酸化塩素ガスによる真菌Alternaria alternataの菌糸成長抑制  [in Japanese] Inhibition of Hyphal Growth of the Fungus Alternaria alternata by Chlorine Dioxide Gas at Very Low Concentrations  [in Japanese]

The efficacy of chlorine dioxide (ClO_2) gas at very low concentrations for hyphal growth of Alternaria alternata related to fungal allergy was evaluated using a fungus detector. The fungus detector is a plastic sheet with a drop of spore-suspending medium, and it makes possible clear observations of hyphal growth with a light microscope. ClO_2 gas (average 0.075 ppm, 0.21μg/l) inhibited hyphal growth of the fungus, but not germination of fungal spores. The hyphal length was more than 1780μm under air conditions (control) and 49±17μm under ClO_2 gas conditions for 72 h. According to the international chemical safety card, threshold limit values for ClO_2 gas are 0.1 ppm as an 8-h timeweight average and 0.3 ppm as a 15 min short-term exposure limit. From these data, we propose that treatment with ClO_2 gas at very low concentrations in space is a useful tool for the growth inhibition of fungi in the fields of food, medicine, etc. without adverse effects.