Product Identification

Product Name

Methyldichlorosilane

Synonyms

Dichloro(methyl)silane
Dichloromethylsilane
Methyl dichlorosilane

CAS

75-54-7

Formula

CH4Cl2Si

Molecular Weight

115.04

EINECS

200-877-1

RTECS

VV3500000

RTECS Class

Primary Irritant

Beilstein/Gmelin

1071194

Beilstein Reference

4-04-00-04096

Physical and Chemical Properties

Appearance

A colorless fuming liquid with a pungent odor.

Solubility in water

Insoluble

Melting Point

-92.8

Boiling Point

41

Vapor Pressure

468 (25 C)

Density

0.93 g/cm3 (0 C)

Partition Coefficient

3.77

Heat Of Vaporization

27.1 kJ/mol

Heat Of Combustion

-1203 kJ/mol

Usage

Monomer for silicone fluids.

Vapor Density

3.97

Refractive Index

1.4 (20 C)

First Aid Measures

Ingestion

Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.

Inhalation

Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration.

Skin

Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Destroy contaminated shoes.

Eyes

Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed. Extensive irrigation is required (at least 30 minutes).

Handling and Storage

Storage

Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Keep under a nitrogen blanket. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area. Do not store in metal containers.

Handling

Wash thoroughly after handling. Use only in a well ventilated area. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Take precautionary measures against static discharges. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. Do not allow contact with water. Use only in a chemical fume hood. Discard contaminated shoes. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.

Hazards Identification

Ingestion

May cause severe and permanent damage to the digestive tract. Causes gastrointestinal tract burns.

Inhalation

Causes chemical burns to the respiratory tract. Inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema. Vapors may cause dizziness or suffocation.

Skin

Causes skin burns.

Eyes

Causes eye burns. May result in corneal injury. May cause conjunctivitis.

Hazards

Difficult to extinguish; reignition may occur. Contact with water applied to adjacent fires will generate irritating hydrogen chloride.

UN (DOT)

1242

Exposure Controls/Personal Protection

Personal Protection

Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear a chemical apron. Wear appropriate protective clothing to minimize contact with skin.

Respirators

A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use. Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.

Fire Fighting Measures

Flash Point

-32

Autoignition

230

Fire Fighting

Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Water Reactive. Material will react with water and may release a flammable and/or toxic gas. Use water spray to keep fire-exposed containers cool. Extremely flammable liquid. Containers may explode in the heat of a fire. Will be easily ignited by heat, sparks or flame. Contact with metals may evolve flammable hydrogen gas. Extinguishing media: DO NOT USE WATER! Do NOT get water inside containers. Do NOT use straight streams of water. Cool containers with flooding quantities of water until well after fire is out. For small fires use dry chemical, soda ash, lime or sand. For large fires use dry sand, dry chemical, soda ash or lime or withdraw.

Upper exp. limit

55

Lower exp. limit

3.4

Fire Potential

Dangerous when exposed to heat or flame flammable liquid. Vapor forms flammable mixtures with air. Pure dichloro(methyl)silane is not ignited by impact, but it is in presence of potassium permanganate or trilead tetraoxide, or by copper or silver oxides, even under an inert gas. Trichlorosilane is highly flammable.

Accidental Release Measures

Small spills/leaks

Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Clean up spills immediately, using the appropriate protective equipment. Remove all sources of ignition. Use a spark-proof tool. A vapor suppressing foam may be used to reduce vapors. Do not get water on spilled substances or inside containers.

Stability and Reactivity

Incompatibilities

Copper, lead oxide, potassium permanganate, oxidizing agents (strong, e.g. bromine, hydrogen peroxide, nitrogen dioxide, potassium nitrate), silver.

Stability

Stable under normal temperatures and pressures.

Decomposition

Hydrogen chloride, carbon monoxide, carbon dioxide, silicon oxide.

Combustion Products

Toxic hydrogen chloride and phosgene gases may be formed.

Transport Information

UN Number

1242

Hazard Class

4.3

Packing Group

I