|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1995 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1994 : ¥1,600,000 (Direct Cost : ¥1,600,000)
No appropriate method has yet been established to investigate ignition dangers of hazardous wastes. We have undertaken in this study a basic experiment in order to create and propose a test method for the determination of the dangers of the wastes of combustible solids with the ignition dangerousness comparable to those cited in "the United Nations Recommendations, Class 4.1" (Orange Book).
The following substances were used as the test materials : metallic powders ; plastics, which are the combustible materials designated by the Fire Service Act ; ignitable solids (the flash point < 40ﾟC) : tetramethoxytitanium, trioxane, and so on ; combustible solids ( the United Nations Recommendations) : naphthalene, paraformaldehyde, and so on ; and common organic materials : anthracene, sawdust, and so on. The simulated wastes were prepared by mixing these substances with aluminium powder and cellulose in various proportions.
The measurment of the dangers was carried out in conformity to the small gas flash ignition test and the Seta closed cup flash point test prescribed by Fire Service Act, and the burning rate test provided by the United Nations Recommendations, Class 4.1. At the same time, the confirmatory test has been carried out for the determination of dangerousness by using digital calorimeter, high-pressure differential thermal balance, and Oxygen Index Method.
Careful analysys of the data obtained from various tests mentioned above led us to recognize the method using the improved type of Oxygen Index Method to be the most relevant one. As a consequence, we conclude that there exists the ignition danger when substance under testing ignited within 10 seconds, continued burning, and terminated within 90 seconds by the contact with the small gas flame under a fixed 21 vol% oxygen concentration in support burning gas (O_2/N_2).