EXPERIMENTAL STUDIES ON THE APPLICATION OF SOME BACTERICIDES AND FUNGICIDES FROM THE VIEWPOINT OF CLOTHES SANITATIONII. ON THE RESIDUAL EFFECTS OF THE PENTACHLOROPHENOL MIXED IN THE INSOLES OF CANVAS SHOES AFTER WASHING

摘要

The results of the experiments are summarized as follows: When the material insoles of canvas shoes, which mixed Na-PCP and Ca-PCP in concentrations of 0.6 to 4.0% in the rubber parts and 2.1% uniformly in the rubber cement part holding together the rubber soles and the canvas, were washed in tap water for 6, 24, 48, 96, 120 and 144 hours, in the case when the materials were first cut into 10 mm diameter circles and then were washed, containing 0.6% in the rubber part, after 96 hours continuous washing, showed entirely no growth of saprophytes and the antibacterial effect remained perfect, but above 120 hours washing, its antibacterial effect decreased and disappeared ; however, compared with the control, the growth of bacteria was slight. The materials contained two to four percent in the rubber part, after 120 hours washing, held a complete antibacterial effect, but after 144 hours washing, only the 4.0% ones held a complete antibacterial effect; nevertheless in the ones contained, less than 2.0% compared with the control, the antibacterial effect was noticed.By the experiments for Trichophyton rubrum, the growth of the fungi was completely prevented after 24 hours continuous washing, but above 48 hours washing, the antifungal action inclined to decrease and above 144 hours, even the ones containing 4.0% did not seem to prevent the growth of fungi.On the contrary, in the case of those washed before cutting the insoles, the antibacterial or antifungal action was considerably superior to those cut before washing, and the flowing of chemicals was known to be a little restricted. To state the practical conditions, it was said to be near the actual condition when the whole insoles were washed as they were, then cut circularly and examined for the antibacterial or antifungal effect.By the above washing tests, the antibacterial and antifungal effect was almost same between Na-PCP and Ca-PCP and it seemed difficult to distinguish the superiority or inferiority of their residual effects.As the practical experiments, the canvas shoes which were mixed with Na-PCP 0, 0.6, 1.0, 2.0 and 4.0% and Ca-PCP 0.6 and 1.0% in the rubber parts, and the same chemicals of 2.1% uniformly in each rubber cement part, were worn for about half a year from the summer to the autumn by eight laboratory members and during these period, for eight hours a day on an average, for 38, 100, and 113 days respectively and were washed several times. Examining the residual effects of antibacterial or antifungal activity of these materials for saprophytes and trichophyton, compared with the control the antibacterial activity was noticed enough, but its effects decreased extremely and the antibacterial or antifungal action of the canvas shoes was known to have a certain restricted period, and its effective period was thought to be within half a year.As the results of the practical experiments, skin disease symptoms as side reactions for the human body were not observed at all and as reported in the first report, the insoles material mixed with PCP was thought to have no toxicity for human body.