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Safety Data Sheet for Trichlorosilane – Part 1: Chemical and Company Identification. Chinese name of the chemical: Trichlorosilane; Common names or trade names of the chemical: Trichlorosilane; English name of the chemical: Trichlorosilane； Silicochloroform Part 2: Composition/Ingredient Information Molecular formula: SiHCl3 Molecular weight: 135.44 Main component: Trichlorosilane content ≥98% ； CAS No.: 10025-78-2 Section 3: Hazard Summary Hazard Class: Category 4.3 Flammable in contact with moisture Routes of exposure: Inhalation, ingestion, absorption through the skin ； Health hazards: It causes severe irritation to the eyes and upper respiratory tract. High concentrations can cause corneal opacity, respiratory inflammation, and even pulmonary edema. Direct eye contact can cause severe burns to the cornea and eyelids. Skin contact can cause tissue necrosis, which does not heal over time ； Environmental hazard: Harmful to the environment ； Flame and explosion hazard: This product is flammable and explosive, classified as a Class 1 material that catches fire easily when exposed to moisture. Section 4: First aid measures. Skin contact: Immediately remove contaminated clothing and rinse with plenty of flowing water for at least 15 minutes. Seek medical attention. Eye contact: Immediately lift the eyelids and rinse thoroughly with plenty of flowing water or saline for at least 15 minutes. Seek medical attention. Inhalation: Quickly move to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. If breathing stops, perform artificial respiration immediately. Seek medical attention. Ingestion: Rinse the mouth with water and give milk or egg white to drink. Seek medical attention. Part 5: Fire-fighting measures. Hazardous properties: Reacts violently with oxidizers. Reacts with water or water vapor to produce heat and toxic, corrosive fumes. Burns or explodes in the presence of open flames or high temperatures ； Harmful combustion products: hydrogen chloride, silicon oxide. Fire extinguishing method: Steam is heavier than air and tends to accumulate in low areas. Steam in enclosed spaces can explode when exposed to fire. If the steam spreads to distant areas and comes into contact with an ignition source, it will catch fire and cause backdrafts. If there is no leakage, use misted water to cool the exposed containers from a safe distance. Firefighters must wear full-body flame- and gas-resistant suits, as well as filter-type gas masks or self-contained breathing apparatus. Extinguishing agents: dry sand, dry powder, carbon dioxide. Precautions and measures for extinguishing fires: Water and foam extinguishers are prohibited. Section 6: Emergency Response to Leaks. Emergency measures: Quickly evacuate people from the area contaminated by the leak to a safe zone, and implement isolation while strictly restricting access. Cut off the source of fire; it is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and protective clothing against toxins. Enter the site from the upwind side. Seal the source of leakage as much as possible. Prevent entry into confined spaces such as sewers and drainage ditches. Minor leaks: Spread sand or non-flammable materials on the ground to absorb the liquid. Use an emulsion made from a non-flammable dispersant for cleaning; dilute the resulting solution and discharge it into the wastewater system. In the event of a large-scale leak: construct dikes or dig pits to contain the liquid, cover it with foam to reduce steam hazards. Use explosion-proof pumps to transfer the liquid into tank trucks or specialized collection containers, for subsequent recycling or disposal at waste treatment facilities. Part 7: Handling, Disposal, and Storage. Handling precautions: Operate in a closed environment with adequate ventilation; operators must receive specialized training and strictly follow the operating procedures. It is recommended that operators wear chemical safety goggles, protective clothing resistant to toxic substances, and acid- and alkali-resistant gloves. Use explosion-proof ventilation systems and equipment. Static electricity grounding should be implemented during filling to prevent its accumulation. Handle the material carefully during transportation. Storage precautions: Store in a cool, dry, and well-ventilated warehouse. The storage temperature should not exceed 25°C, and the relative humidity should not exceed 75%. The packaging must be sealed to prevent moisture from getting in. It should be stored separately from oxidizers, acids, and bases; mixed storage is strictly prohibited. The use of mechanical equipment and tools that generate sparks is prohibited. Regular checks should be carried out to detect any leaks. The storage area should be equipped with emergency equipment for dealing with leaks as well as appropriate containment materials. Part 8: Exposure Control/Personal Protection China MAC: No standard established ； Former Soviet Union MAC: No standards established. Detection method: Gas chromatography. Engineering controls: Operate in a sealed environment; ensure proper ventilation. Mechanize and automate as much as possible. Provide safety showers and eye wash stations ； Respiratory protection: When the air concentration exceeds the permissible level, it is necessary to wear a self-priming filter-type gas mask (full-face mask) or an isolated respirator. It is recommended to wear an air respirator during emergency rescue or evacuation. Eye protection: Protection is provided through respiratory protection. Body protection: Wear rubber-coated gas-proof clothing. Hand protection: Wear rubber gloves. Other protections: Smoking, eating, and drinking are prohibited at the work site. Work done, take a shower. Store the clothes contaminated with toxins separately and wash them before using them again. Maintain good hygiene* habits. Section 9: Physical and Chemical Properties Appearance and Characteristics: Colorless liquid, highly volatile, with an oppressive odor. Melting point (°C): -134°C Boiling point (°C): 31.8°C Relative density (water = 1): 1.37 Relative vapor density (air = 1): 4.7 Saturated vapor pressure (kPa): 55.33 (14.5°C) Heat of combustion (kJ/mol): Data not available Critical temperature (°C): Data not available Critical pressure (MPa): Data not available Flash point (°C): -13.9 Ignition temperature (°C): Data not available Upper explosive limit (% V/V): 70 Lower explosive limit (% V/V): 6.9 Solubility: Miscible with most organic solvents such as benzene and ether. Primary use: Used in the manufacture of coupling agents and silicon compounds ； Part 10: Stability and Reactivity Stability: Stable Conditions to be avoided: Humid air Incompatible substances: Strong oxidizing agents, alcohols, water, strong bases. Aggregate hazards: Does not aggregate. Part XI: Toxicological data. Acute toxicity: LD50: 1030 mg/kg (oral, mice); LC50: 15000 mg/kg (oral, rats). Subacute and chronic toxicity: Irritation: Sensitization: Mutagenicity: Teratogenicity: Carcinogenicity. Part XII: Ecological data. Ecotoxicological toxicity: Biodegradability: Non-biodegradability: Bioaccumulation: Other harmful effects. Part XIII: Disposal. Methods of disposal: Dispose in accordance with the requirements of ** and relevant local regulations. Or contact the supplier or manufacturer to determine the disposal method. Part XIV: Transport Information Hazardous goods code: 43049 UN number: 1818 Packaging mark: Flammable when wet Packaging category: Class II Packaging method: Steel drums with small openings, plastic bottles, or metal drums/tanks, enclosed in ordinary wooden boxes. Transportation precautions: When transporting by rail, it is necessary to follow strictly the loading guidelines specified in the Ministry of Railways’ rules for the transportation of hazardous goods. The packaging must be intact at the time of shipment, and the goods must be loaded securely. During transportation, it is essential to ensure that the containers do not leak, collapse, or get damaged. It is strictly prohibited to transport these goods together with oxidizers, alkalis, acids, or other food-related chemicals. Emergency equipment for dealing with leaks should be available during transportation. The goods must be protected from sunlight, rain, and high temperatures during transit. When transported by road, it is necessary to follow the designated routes and avoid stopping in residential areas or densely populated zones. Part 15: Regulatory information Domestic regulations on chemical safety management include the Regulations on the Safety Management of Hazardous Chemicals (issued by the State Council on January 26, 2002), the Detailed Rules for the Implementation of the Regulations on the Safety Management of Chemical Hazardous Materials (Document No. Hualao Fa 677), and the Provisions on the Safe Use of Chemicals in the Workplace (Document No. Laobu Fa 423). These regulations set out requirements regarding the safe use, production, storage, transportation, and handling of chemical hazardous materials ； The Classification and Labelling of Commonly Used Hazardous Chemicals (GB 13690-92) classifies this substance as a Category 4.3 flammable material when exposed to moisture. Part 16: Other Information Department responsible for filling in the form: Time of filling in the form: Department responsible for data verification: Notes on modifications: References: Synthesis of trichlorosilane: Silica powder is unloaded onto a rotating disk, transported via pipes to a silica powder storage bin, then fed into a silica powder dryer. After being measured by a disk feeder, it is added to the trichlorosilane synthesis furnace. Inside the trichlorosilane synthesis furnace, the temperature is maintained between 80–310°C, where silicon powder reacts with hydrogen chloride to produce trichlorosilane and silicon tetrachloride. The generated trichlorosilane and silicon tetrachloride gases have dust and higher chlorosilanes removed through settlers, cyclone separators, and bag filters; after water cooling, they are pressurized by diaphragm compressors and then condensed into a liquid using a coolant at -35°C. Non-condensable gases enter the exhaust gas scrubber through a liquid seal tank, and are discharged after being purified to meet the required standards through acid and alkali scrubbing. Separation of trichlorosilane: A mixture of trichlorosilane and silicon tetrachloride (with a trichlorosilane content of 80–85%) is fed into a pressurized tower, where continuous purification and separation are carried out using two towers. By controlling the reflux ratio, a product with a trichlorosilane content of over 99% and a by-product with a silicon tetrachloride content of over 95% are obtained as the final products. The dust-containing exhaust gas is mainly nitrogen used to transport silicon powder; the silicon powder is first recovered using bag filters, and then the gas is washed with water. The wastewater from this washing process is settled before being reused, while the exhaust gas after washing is released into the atmosphere. The dust removal efficiency of the bag filter is 99%, while that of the washing system is 50%; thus, the overall dust removal efficiency reaches 99.5%, ensuring that the emissions meet the required standards after treatment. Inert gases mainly consist of shielding gases, with small amounts of chlorosilanes, hydrogen chloride, and others also present. The non-condensable gas remaining after low-temperature condensation is sent to the waste gas treatment unit. Chlorosilane compounds decompose rapidly upon contact with water to form silicic acid and hydrogen chloride. The hydrogen chloride gas is first absorbed in a cycle using dilute hydrochloric acid to be recovered as concentrated hydrochloric acid, while a trace amount of it is absorbed and reacted by an alkaline solution. The main component of the exhaust gas is nitrogen; after being treated through washing, the exhaust gas is discharged in compliance with standards via the workshop exhaust stack. Where possible, choose equipment with a low speed and low noise level, as long as the requirements are met ； At the same time, a separate soundproof room is provided for the blower, separated from the floor it is located on, in order to reduce noise caused by vibrations ； Silencers are installed on the intake pipes of air compressors, blowers, pumps, etc., and sound-insulated operation rooms are provided to reduce indoor noise pollution and improve the working environment for workers. The chimney is installed at a sufficient height to ensure that the emission of smoke meets the requirements of the second-level standards set out in the **Comprehensive Emission Standards for Air Pollutants**. The hydrosilic chloride method involves using metallurgical-grade silicon powder as a raw material and reacting it with hydrogen chloride gas. Copper or iron-based catalysts can be used. The reaction is carried out at pressures of 200–800 and 0.05–3 MPa: 2Si + HCl ====== HSiCl3 + SiCl4 + 3H2. The reactors used for this reaction have evolved from fixed-bed reactors, stirred-bed reactors to fluidized-bed reactors. The process has also evolved from batch to continuous. The reactor is made of carbon steel. The target particles are added to the reactor in advance; after it is heated to the desired temperature, hydrogen chloride gas is continuously introduced from the bottom. The products and unreacted materials are continuously removed, and after dust removal and purification, they are used to produce high-purity polycrystalline silicon and high-purity silane. The aforementioned reaction is exothermic, with an enthalpy of -141.8 kJ per mole. Raising the temperature helps to increase the reaction rate, but it simultaneously reduces the selectivity for trichlorosilane. By optimizing the reaction temperature, the selectivity for trichlorosilane can be significantly improved. For example, when silicon is reacted with hydrogen chloride at temperatures of 300–425 degrees and pressures of 2 to 5 kPa, the product is produced at a rate of 600–1000 kilograms per hour; the selectivity for trichlorosilane is as high as 80–88%. The by-products include dichlorosilane in a mass fraction of 1%–2% and polymeric compounds in a mass fraction of 1–4%, with the remainder being silicon tetrachloride. The moisture content in hydrogen chloride gas has a significant impact on the yield of trichlorosilane. Therefore, it must be dried strictly. The reaction between silicon and hydrogen chloride to form trichlorosilane is presumed to be a zero-order reaction; when silicon materials with a purity of over 99.99% are used, the yield of silane is low. Studies were conducted in a microreactor, and the results showed that aluminum, an impurity present in metallurgical-grade raw materials, acts as a catalyst for the reaction, allowing the reaction temperature to be reduced and the yield of trichlorosilane to increase. The hydrogenation of silicon tetrachloride method: 3SiCl4 + 2H2 + Si ====> 4HSiCl3. The reaction temperature ranges from 400 to 800°C, while the pressure is between 2 and 4 MPa. This is an equilibrium reaction; to increase the yield of trichlorosilane, it is preferable to carry out the reaction in the presence of hydrogen chloride. Using metallurgical-grade raw materials and removing the surface oxides through pre-activation can further improve the yield of trichlorosilane. The boiling points of trichlorosilane and silicon tetrachloride differ by 25 degrees, and no azeotropes are formed, making separation relatively easy. A method for producing trichlorosilane by hydrogenation of silicon tetrachloride, the main steps of which are as follows: a) Nickel catalyst and silicon powder are uniformly mixed in a mass ratio of 1–10%, and then placed in an activator; the activation conditions involve an H2 flow rate of ≥0.05–0.3 m/s, with the activation process taking place over different time periods at rising temperatures from 25°C to a final temperature of 420°C ； b) The liquid phase temperature of silicon tetrachloride (SiCl4↓) is maintained at 60–119°C in the storage tank, the total pressure of the gas phase is 1.5 MPa, and the molar ratio of H2↓ to SiCl4↓ in the mixture at the outlet is 1–10 ； c) In the hydrogenation reactor, a mixture of H2↓ and SiCl4↓ passes through a layer of catalyst mixed with silicon powder, at a temperature of 400–500°C and a pressure of 1.2–1.5 Mpa ； d) The mixed gas at the outlet of the hydrogenation reactor is passed through a dust collector for dust removal and filtration; thereafter, chlorosilane is separated out in liquid form in a condenser, while the non-condensable H2 gas is returned to the storage tank for reuse ； e) After being distilled in a distillation tower, the heavier components SiCl4↓ are returned to the storage tank for reuse.