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A colorless fuming liquid with a pungent odor. Flash point:-26°F; Boiling point: 41°C (106°F) . Vapors heavier than air. Vapor and liquid may cause burns. Denser than water and decomposed by water to form hydrochloric acid, a corrosive material.

Chlorosilanes, such as METHYLDICHLOROSILANE, are compounds in which silicon is bonded to from one to four chlorine atoms with other bonds to hydrogen and/or alkyl groups. Chlorosilanes react with water, moist air, or steam to produce heat and toxic, corrosive fumes of hydrogen chloride. They may also produce flammable gaseous H2. They can serve as chlorination agents. Chlorosilanes react vigorously with both organic and inorganic acids and with bases to generate toxic or flammable gases. Impact of dichlorosilane causes mixtures to burst into flame. This is the case, when the dichlorosilane and most likely related substances are mixed with oxidants such as potassium permanganate, lead oxide, copper oxide, or silver oxide, even under inert gas atmosphere [Bretherick, 1995, pg. 193]. With METHYLDICHLOROSILANE, toxic hydrogen chloride and phosgene gases may be formed when burned.

Flammable, dangerous fire risk. Very toxic.

Inhalation causes irritation of respiratory tract; heavy exposure can cause pulmonary edema. Contact of liquid with skin or eyes causes severe burns. Ingestion causes burns of mouth and stomach.

This material is used to make siloxanes and other silicone polymer (polysiloxane) materials. Incompatibilities: May form explosive mixture with air. Reacts violently with water producing heat, corrosive hydrochloric acid and flammable hydrogen. Methyl dichlorosilane may spontaneously ignite on contact with air (even under inert gas) and on contact with potassium permanganate, lead(II) oxide; copper oxide; silver oxide. Violent reaction with oxidizers. Decomposes on contact with hot surfaces or flames producing toxic and corrosive fumes including silicon oxides, hydrogen chloride, and phosgene. Decomposes on contact with alkaline compounds producing highly flammable hydrogen gas. Corrodes many metals in presence of water. Attacks some plastics, rubber and coatings.

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 30 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. If victim is conscious, administer water or milk. Do not induce vomiting. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.

UN1242 Methyldichlorosilane Hazard Class: 4.3; Labels: 4.3-Dangerous when wet material; 8-Corrosive material, 3-Flammable liquid.

Methyl dichlorosilane, is a colorless liquid with a sharp irritating odor. It is a dangerous fire risk, corrosive, and water reactive. The flammable range is wide, from 6% on the lower end to 55% on the upper end. Boiling point is 107°F (41°C), flash point is 15°F (?9°C), and ignition temperature is more than 600°F (315°C). Specific gravity is 1.11, which is heavier than water. Vapors are heavier than air and will travel to ignition sources. It is immiscible in water and decomposes on contact to release hydrogen chloride gas. Methyl dichlorosilane is toxic by inhalation and skin absorption; it is irritating to the skin, eyes, and respiratory system. Contact with the material may cause burns to the eyes and skin. The four-digit UN identification number is 1242. The NFPA 704 designation is health 3, flammability 3, and reactivity 2. The white space at the bottom of the diamond has a W with a slash through it, indicating water reactivity. The primary use is in the manufacture of siloxanes, which are straight-chained compounds similar to paraffin hydrocarbons.

Colorless clear liquid

Methyl dichlorosilane is a clear, straw-colored liquid.

See “Spill Handling.”

Provides better diastereoselective reductive aldol reactionbetween an aldehyde and an acrylate ester than othersilanes. Forms high-boiling polymeric by-products uponaqueous work-up.

Reactivity with Water Reacts violently to form hydrogen chloride (hydrochloric acid); Reactivity with Common Materials: Reacts with surface moisture to evolve hydrogen chloride, which is corrosive to common metals; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Flood with water, rinse with sodium bicarbonate or lime solution; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.

(1) Color Code—Red: Flammability Hazard: Storein a flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.(2) Color Code—Blue: Health Hazard/Poison: Store in asecure poison location. (3) Color Code—White: Corrosive orContact Hazard; Store separately in a corrosion-resistantlocation. Prior to working with this chemical you should betrained on its proper handling and storage. Before enteringconfined space where this chemical may be present, check tomake sure that an explosive concentration does not exist.Methyl dichlorosilane must be stored to avoid contact withwater, since violent reactions occur once hydrogen chlorideis produced. Store in tightly closed containers in a cool, wellventilated area away from heat. Sources of ignition, such assmoking and open flames, are prohibited where methyldichlorosilane is handled, used, or stored. Metal containersinvolving the transfer of 5 gallons or more of methyl dichlorosilane should be grounded and bonded. Drums must beequipped with self-closing valves, pressure vacuum bungs,and flame arresters. Use only nonsparking tools and equipment, especially when opening and closing containers ofmethyl dichlorosilane. Wherever methyl dichlorosilane isused, handled, manufactured, or stored, use explosion-proofelectrical equipment and fittings.

Impurities are generally other chloromethyl silanes. Distil it through a conventional Stedman column (p 11) of 20 theoretical plates or more. It should be protected from H2O by storing over P2O5. [Stck & Somieski Chem Ber 52 695 1919, Sauer J Am Chem Soc 68 962 1946, Beilstein 4 IV 4096.]

Forms explosive mixture with air. Reactsviolently with water producing corrosive hydrochloric acid.Methyl dichlorosilane may spontaneously ignite on contactwith air (even under inert gas) and on contact with potassium permanganate, lead(II) oxide, copper oxide, silveroxide. Violent reaction with oxidizers. Decomposes on contact with hot surfaces or flames producing toxic and corrosive fumes including silicon oxides, hydrogen chloride, andphosgene. Decomposes on contact with alkaline compoundsproducing highly flammable hydrogen gas. Corrodes manymetals in presence of water. Attacks some plastics, rubber,and coatings.