colorless. Flammable. Toxic corrosive gas with pungent odor. Melting point -122°C. Boiling point 8.2 ℃. Gas relative density (air = 1) 4.599; liquid relative density d4}-122>. 1.42. Critical temperature 176.3 ℃. Vapor pressure (Chemicalbook 20°C, absolute pressure) 0.15Mpa. Specific volume (20°C, 1.0133×105Pa) 239mI/g. The explosion limit in air is 1.3% to 98%. Reacts violently with water. Hydrolyzed in humid air to generate hydrochloric acid mist. There is strong corrosiveness. Used in semiconductor manufacturing, especially epitaxy processes as a silicon source. For polysilicon epitaxial growth and chemical vapor deposition of silicon dioxide and silicon nitride in the electronics industry