Uses
In enamels for china and porcelain; manufacture of opal glass; as insecticide, rodenticide; mothproofing of woolens. Fluoridating agent for drinking water. Intermediate in production of synthetic cryolite.
General Description
Fine, white, odorless, powdered solid. Toxic by ingestion, inhalation and skin absorption. Used as a rodenticide.
Reactivity Profile
SODIUM FLUOROSILICATE(16893-85-9) has weak oxidizing or reducing powers. Redox reactions can however still occur. The majority of compounds in this class are slightly soluble or insoluble in water. If soluble in water, then the solutions are usually neither strongly acidic nor strongly basic. These compounds are not water-reactive.
Air & Water Reactions
Water soluble.
Hazard
Toxic by ingestion and inhalation, strong
irritant to tissue.
Health Hazard
Inhalation of dust may irritate nose and throat. Ingestion causes symptoms similar to fluoride poisoning; compound is highly toxic; initial symptoms include nausea, cramps, vomiting, diarrhea, and dehydration; in severe cases, convulsions, shock, and cyanosis are followed by death in 2-4 hr. Contact with eyes causes irritation. Contact with skin causes rash, redness, and burning, sometimes followed by ulcer formation.
Potential Exposure
Sodium hexafluorosilicate is as a rodenticide; as an intermediate in production of synthetic cyrolite; as an insecticide in delousing and in mothproofing of woolens.
Fire Hazard
Behavior in Fire: Decomposes at red heat
First aid
Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. 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.
Shipping
UN2674/Sodium fluorosilicate, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Reacts with acids to produce hydrogen fluoride, a highly corrosive and poisonous gas.
Production Methods
Sodium hexafluorosilicate is typically produced through a neutralisation reaction between fluorosilicic acid and a sodium salt such as sodium chloride or sodium sulphate. In this process, fluorosilicic acid, often a byproduct of phosphate fertiliser production, is reacted with the sodium salt in an aqueous solution, forming sodium hexafluorosilicate and releasing hydrochloric acid as a byproduct.
Purification Methods
Crystallise it from hot water (40mL/g) by cooling.
Flammability and Explosibility
Nonflammable
Industrial uses
Sodium fluorosilicate (Na2SiF6) is a white, isomorphous powder. Solubility in water is similar to that of NaF. In
acid pH, solubility improves.
Commercially, Na2SiF6 is produced by treatment of fluorosilic acid with sodium chloride,
as shown in the following reaction:
H2SiF6 + 2NaCl = Na2SiF6 + 2HCl
Mechanism of action
Acts by releasing fluoride ions, which interfere with enzyme activity in insects, leading to neurological disruption, paralysis, and death
Materials Uses
Research showed that the sodium fluorosilicate material could potentially be used as a reliable precursor in the synthesis of fluoride and silicon based materials due to its acceptable physical properties, chemical purity and thermal behavior[1].
Toxics Screening Level
The initial threshold screenin level (ITSL) for sodium silicoluoride (Na2SiF6) is 250 μg/m3 based on a 8 hour averaging time.
References
[1] Arianpour, F., Arianpour, A. Ç., & Aali, B. (2020). Characterization and Properties of Sodium Hexa-Fluorosilicate and its Potential Application in the Production of Sodium Fluoride. Silicon, 13 12, 4381–4389.
https://doi.org/10.1007/s12633-020-00755-0
Pesticide Type
Insecticide; Veterinary substance
