Product Identification

Product Name

Tetramethoxysilane

Synonyms

Methyl silicate
Tetramethyl orthosilicate

CAS

681-84-5

Formula

C4H12O4Si

Molecular Weight

152.22

EINECS

211-656-4

RTECS

VV9800000

RTECS Class

Other

Beilstein/Gmelin

1699658

Beilstein Reference

4-01-00-01266

EC Class

flammable, very toxic, irritant

Physical and Chemical Properties

Appearance

Clear colorless liquid.

Solubility in water

Insoluble

Melting Point

-2

Boiling Point

121

Vapor Pressure

18 (25 C)

Density

1.02 g/cm3 (20 C)

Partition Coefficient

2.97

Heat Of Vaporization

37.1 kJ/mol

Heat Of Combustion

-2906 kJ/mol

Usage

In coating picture screens of television picture tubes.

Vapor Density

5.3

Saturation Concentration

16000 ppm (1.6%) at 25 C (calculated)

Refractive Index

1.3683 (20 C)

First Aid Measures

Ingestion

Do not induce vomiting. Give copious amounts of water and seek immediate medical attention.

Inhalation

Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.

Skin

Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists.

Eyes

Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.

Handling and Storage

Storage

Store in closed container in a dry location. Keep away from sources of ignition and heat.

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.

Hazards Identification

Ingestion

See Inhalation.

Inhalation

Corrosive. Causes burns. Highly destructive to skin, eyes, mucous membranes and upper respiratory tract. Ingestion or inhalation could prove fatal. Spasms, inflammation and edema of the lungs.

Skin

See Inhalation.

Eyes

See Inhalation.

Hazards

Vapors form explosive mixtures with air: indoors, outdoors, and sewers explosion hazards. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapors may travel to source of ignition and flash back. Substance will react with water (some violently) releasing flammable, toxic or corrosive gases and runoff. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water.

EC Risk Phrase

R 10 23 34 37 41

EC Safety Phrase

S 26 28 36/37/39 45

UN (DOT)

2606

Exposure Controls/Personal Protection

Personal Protection

Wear appropriate protective gloves, clothing and goggles.

Respirators

Wear positive pressure self-contained breathing apparatus (SCBA).

Exposure limit(s)

TLV: 1 ppm; 6 mg/m3 (ACGIH 1997). NIOSH REL: TWA 1 ppm (6 mg/m3)

Poison Class

2

Fire Fighting Measures

Flash Point

26

Autoignition

240

Fire Fighting

Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Use foam, dry chemical, or carbon dioxide. Keep run-off water out of sewers and water sources.

Fire Potential

HIGHLY FLAMMABLE.

Accidental Release Measures

Small spills/leaks

Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Disperse vapors using fans or blowers. Land spill: Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. Water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses.

Stability and Reactivity

Stability

No data.

Incompatibilities

Oxidizers, hexafluorides of rhenium, molybdenum & tungsten.

Decomposition

Carbon monoxide, hydrogen cyanide and oxides of nitrogen.

Combustion Products

Fire will produce irritating, corrosive and/or toxic gases.

Transport Information

UN Number

2606

Hazard Class

6.1

Packing Group

I

HS Code

2920 90 85