SILICON TETRAFLUORIDE SiF4
General Characteristics
Silicon Tetrafluoride is a colorless, toxic, nonflammable gas with a suffocating odor. It is irritating to the mucous membranes. Silicon Tetrafluoride forms fumes in humid air, and hyrolyses rapidly to form fluorosilicic acid and hydrogen fluoride. It is shipped as a free gas, and the contents vary with the pressure.
Physical Information
Molecular Weight
104.08
Flammability Limits in air
Nonflammable
Specific Gravity,
Gas @ 70&degF(21.1&degC),
1 atm(Air=1)
3.55
Density,
Gas @ 70&degF(21.1&degC), 1 atm
0.266lb/ft^3 (4.26g/l)
Specific Volume,
Gas @ 70&degF(21.1&degC), 1 atm
3.76ft^3/lb (0.23l/g)
Sublimation Point @ 1 atm
-139.2&degF (-95.1&degC)
Freezing Point @ 1 atm
-130&degF (-90&degC)
Critical Temperature
6.5&degF (-14.2&degC)
Critical Pressure
538.8 psia (37.2 bar)
Toxicity (as HF, a 4 to 1 ratio)
PEL /TLV
3 ppm
STEL
6 ppm
LC50
450 ppm
IDLH
38 ppm