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General Characteristics

Hydrogen Selenide is a colorless, flammable, extremely toxic gas with a very unpleasant odor. It begins to dissociate at approximately 160&degC. It decomposes in air to form a red selenium precipitate. It is shipped as a liquefied gas under its own vapor pressure.

Physical Information

Molecular Weight

80.97

Flammability Limits in air

Not Available

Specific Gravity,
Gas @ 70&degF(21.1&degC),
1 atm(Air=1)

2.8

Density,
Gas @ 70&degF(21.1&degC), 1 atm

0.209lbs/ft^3 (3.34g/l)

Specific Volume,
Gas @ 70&degF(21.1&degC), 1 atm

4.80ft^3/lb (0.301l/g)

Boiling Point @ 1 atm

-43.6&degF (-42.0&degC)

Melting Point @ 1 atm

-86.6&degF (-65.9&degC)

Critical Temperature

280.4&degF (138.0&degC)

Critical Pressure

1293.2 psia (89 bar)

Toxicity

PEL/TLV

0.05 ppm

LC50

2 ppm

IDLH

2 ppm