Fire Safety Science Digital Archive

Recently, a variety of gases have been used in advanced technological industries, such as a semiconductor industry. There are several highly reactive gases among them. Fluorine is one of the representative gases which have very high reactivity. Its high reactivity has been known qualitatively for a long time. But its quantitative hazard has not been assessed yet. In this study, a flammability area of a CO/F2/N2 mixture was determined experimentally, and designated in a triangular diagram. And, a flammability area of a SiH4/CF3OF/N2 mixture was also determined and designated in a triangular diagram. CF3OF is a product of a reaction between CO and F2, which are components of the first mixture, and used as an etching or a cleaning gas in a semiconductor industry. Namely, there is a possibility of accidental mixing between SiH4 and CF3OF. SiH4 is a material of silicon based semiconductors. The flammability diagrams obtained in this study are indispensable for safe handling of these gases.