Silane

  • Silicon hydride
  • Silicon tetrahydride
Formula
SiH4
Structure
Description
Gas. Repulsive odor.
Uses
Source of hyperpure silicon for semiconductors.

Registry Numbers and Inventories.
CAS
7803-62-5
EC (EINECS/ELINCS)
232-263-4
RTECS
VV1400000
RTECS class
Mutagen
UN (DOT)
2203
Merck
12,8633
Beilstein/Gmelin
274 (G)
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
H4Si(1+)
Formula mass
32.11
Melting point, °C
-184.67
Boiling point, °C
-107.17
Vapor pressure, mmHg
530 (-118 C)
Vapor density (air=1)
1.13
Density
0.557 g/cm3
Solubility in water
Decomposes
Heat of fusion
0.67 kJ/mol

Hazards and Protection.
Storage
Store in a cool, dry, well ventilated location. Separate from alkalies, oxidizing materials, halogens, and air. Outside or detached storage is preferred.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Stability
Stable at ordinary temperature; completely decomp at approx 400 C into silicon and hydrogen; decomp by an electric dischage. he substance may spontaneously ignite on contact with air.
Incompatibilities
Reacts with water to form silicon hydroxides and hydrogen gas.
Decomposition
The silanes decomposition at elevated temp to liberate hydrogen and deposit a high purity silicon, which leads to some of the principal uses of silanes.

Fire.
Upper exp. limit, %
100
Lower exp. limit, %
1.37
Fire fighting
Do not extinguish fire unless flow can be stopped. Do not apply water to point of leak in tank car or container. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use alcohol foam, dry chemical or carbon dioxide.
Fire potential
EXTREMELY FLAMMABLE.
Hazards
Silane will ignite spontaneously in air. May polymerize explosively when heated or involved in a fire. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Containers may explode when heated. Ruptured cylinders may rocket.
Combustion products
Fire may produce irritating and/or toxic gases.
Health
1
 
Flammability
4
 
 
Reactivity
3
 

Health.
Exposure limit(s)
TLV (as TWA): 5 ppm; 6.6 mg/m3 (ACGIH 1996). NIOSH REL: TWA 5 ppm (7 mg/m3)
Exposure effects
   Ingestion
Nausea, vomiting and diarrhea are possible if ingested.
   Inhalation
Cough, tachypnea, and wheezing are common after inhalation.
   Skin
Redness, swelling and pain may occur.
   Eyes
Irritants may cause swelling, redness and pain at any site, especially at mucous membranes. The mouth, nose, and eyes are susceptible to these effects.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Vapors may cause dizziness or asphyxiation without warning. May be toxic if inhaled at high concentrations.
   Skin
Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite.
   Eyes
Flush with running water for at least 20 minutes.

Transport.
UN number
2203
Response guide
Hazard class
2.1
Std. Transport #
4905406