Trimethylborane

  • Tirmethylboron
Formula
C3H9B
Structure
Description
Colorless gas.
Uses
Trimethylboron is used as an organometallic precursor for the CVD of boron-carbon containing films and as a boron source in the deposition of borophosphosilicate glass (BPSG).

Registry Numbers and Inventories.
CAS
593-90-8
EC (EINECS/ELINCS)
209-816-3
7 23 26 36/37/39 43 45
UN (DOT)
3160
Beilstein/Gmelin
25372 (G)
Swiss Giftliste 1
G-3010

Properties.
Formula
C3H9B
Formula mass
55.92
Melting point, °C
-162
Boiling point, °C
-22
Vapor density (air=1)
907 (25 C)
Solubility in water
Slightly soluble
Heat of vaporization
25.6 kJ/mol

Hazards and Protection.
Storage
Keep tightly closed. Keep away from heat, sparks, and open flame. Cylinder temperature should not exceed 125 F (52 C).
Protection
Wear appropriate government approved respirator, chemical-resistant gloves, safety goggles, other protective clothing.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Make no contact with the spilled material. ELIMINATE all ignition sources, combustibles and ground all equipment. Fully encapsulating, vapor protective clothing should be worn for spills and leaks with no fire. Stop leak if you can do it without risk. Do not direct water at spill or source of leak. If possible, turn leaking containers so that gas escapes rather than liquid. Isolate area until gas has dispersed. CHLOROSILANES, use AFFF alcohol-resistant medium expansion foam to reduce vapors.
Stability
Stable at normal temperatures and pressures. Reactions to Avoid: Reacts violently with:
Incompatibilities
Water, Strong oxidizing agents, Halogens.
Decomposition
Borane/boron oxides, Methane gas.

Fire.
Flash Point,°C
-45
Fire fighting
For small fires, use cry chemical, CO2, water spray or alcohol-resistant foam. For large fires, use water spray, fog or alcohol-resistant foam. FOR CHLOROSILANES, DO NOT USE WATER; use AFFF alcohol-resistant medium expansion foam.
Fire potential
Flammable; may be ignited by heat, sparks or flames. May form explosive mixtures with air.
Hazards
Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back.
Combustion products
Fire will produce irritating, corrosive and/or toxic gases.

Health.
Poison_Class
2
Exposure effects
Toxic. Reacts violently with water. Spontaneously flammable in air. Toxic by inhalation and in contact with skin.
   Inhalation
May be toxic/fatal if inhaled. Contact may cause burns, severe injury and/or frostbite.
   Skin
May be toxic/fatal if absorbed through skin. Contact may cause burns, severe injury and/or frostbite.
   Eyes
Contact may cause burns, severe injury and/or frostbite.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. In case of contact with liquefied gas, thaw frosted parts with lukewarm water.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
3160
Response guide
Hazard class
2