Chinese name: calcium silicide
Catalogue of hazardous chemicals Serial number: 839
English name: Calcium silicide
UN No.: 1405
Molecular formula: CaSi2
Molecular weight: 68.16
CAS No.: 12013-55-7
Physical and chemical properties
Appearance and character
White powder or vitreous solid.
Melting point (℃)
Relative density (water=1)
two point five
Boiling point (℃)
Saturated vapor pressure (kPa)
Insoluble in water, soluble in acid and alkali..
Toxicity and health hazards
LD50: 9200mg/kg (rat vein).
Irritating and corrosive to eyes, skin and mucous membrane.
Risk of combustion and explosion
Combustion decomposition products
Silicon oxide, calcium oxide.
Flash point (℃)
Upper explosive limit (g/m3):
Autoignition temperature (℃)
540 (dust cloud)
Lower explosive limit (g/m3):
It reacts strongly with water and emits hydrogen which is easy to explode and catch fire. When encountering acid, it emits silicon hydride gas which is easy to spontaneous combustion. It reacts violently with fluorine. Powder and air can form explosive mixture.
Fire risk classification according to building regulations
Acids, water, fluoride.
Fire fighting methods
Dry powder and sand. Water and foam are prohibited.
First aid measures
Skin contact: seek medical advice. In case of burns, treat as alkali burns. Eye contact: open the eyelids and rinse with flowing water for 15 minutes. Get medical attention. Inhalation: leave the site to a place with fresh air. Give oxygen when breathing is difficult. When breathing stops, perform artificial respiration immediately. Get medical attention. Ingestion: Take milk, soybean milk or egg white orally and consult a doctor.
Isolate the leakage pollution area, set warning signs around, and cut off the fire source. It is recommended that emergency personnel wear gas masks and chemical protective clothing. Do not directly contact the leakage, do not directly spray water on the leakage, and do not let water enter the packaging container. Absorb it with dry sand or similar substances, send it to an open place, add a large amount of water in small quantities one by one, mix with it, and put the diluent into the wastewater system after reaction. If there is a large amount of leakage, it shall be collected and recycled or discarded after harmless treatment.
Storage precautions: Store in a cool, dry and well ventilated non combustible warehouse. Keep container sealed. Protect from moisture and rain. It shall be stored separately from acids, moist articles, halogens (fluorine, chlorine, bromine), etc. It is prohibited to use mechanical equipment and tools that are easy to generate sparks. Fire fighting equipment of corresponding types and quantities shall be provided. Handle with care to prevent damage to packaging and containers. Smoking, drinking and eating are not allowed at the operation site. Pay attention to personal protection during subpackaging and handling. Precautions for transportation: The transportation vehicles shall be equipped with fire fighting equipment of corresponding types and quantities and leakage emergency treatment equipment. It is better to transport in the morning and evening in summer. The tank (tank) truck used for transportation shall be equipped with grounding chain, and hole partition can be set in the tank to reduce static electricity generated by vibration. During transportation, it shall be protected from sun exposure, rain and high temperature. Keep away from kindling, heat source and high temperature area during stopover. The exhaust pipe of the vehicle transporting this article must be equipped with a fire retardant device. It is prohibited to use mechanical equipment and tools that are easy to generate sparks for loading and unloading. Road transportation shall be carried out according to the specified route, and shall not stay in residential areas and densely populated areas. It is forbidden to slip during railway transportation. It is strictly prohibited to use wooden ships or cement ships for bulk transportation.