Sodium Tungstate: Uses and Toxicity

Sodium tungstate (Na₂WO₄) is an inorganic compound with various applications across different fields. Sodium tungstate appears as a colorless or white crystalline powder that weathers in dry air, loses its crystallization water at 100°C, is soluble in water, and insoluble in ethanol. It has a relative density of 3.23–3.25 and a melting point of 698°C (anhydrous). Sodium tungstate is obtained by digesting tungsten ore in alkali, with the economically valuable form being tungstate. Sodium tungstate can also be produced by treating tungsten carbide with a mixture of sodium nitrate and sodium hydroxide in a molten process, which overcomes the highly exothermic reaction involved.

Sodium tungstate

Sodium Tungstate Uses

The applications of sodium tungstate span multiple industries:

Chemical Industry

Catalyst: Sodium tungstate is used as a catalyst to accelerate chemical reactions without undergoing significant changes itself. In organic chemistry, sodium tungstate is utilized as a catalyst for olefin epoxidation and alcohol oxidation to aldehydes or ketones.

Major Source of Tungsten: Sodium tungstate is an important intermediate in tungsten extraction. Tungsten is widely used in producing high-speed steel, high-temperature alloys, and catalysts. The primary sodium tungstate uses involve extracting tungsten from ore, as most tungsten ores exist in the form of tungstates. Other applications of sodium tungstate are relatively limited.

Petrochemical Industry

During oil refining, sodium tungstate serves as a desulfurization catalyst, aiding in the removal of sulfur compounds from crude oil to meet environmental regulations and produce cleaner fuels.

Textile Industry

In the textile industry, sodium tungstate is used as a fabric weighting agent. Its mixture, which also includes ammonium sulfate and ammonium phosphate, enhances the flame retardant and waterproof properties of fibers. These treated fibers are used in producing fire-resistant rayon and artificial cotton, and the material is also suitable for leather tanning processes.

Mining and Metallurgy

In ore processing, sodium tungstate is employed to extract tungsten, facilitating the production of tungsten metal and alloys.

Electroplating

In electroplating processes, sodium tungstate provides protective and decorative coatings, enhancing the durability, corrosion resistance, and appearance of plated objects.

Dye Industry

Sodium tungstate is used in mordants, pigments, dyes, and inks.

Photography

Historically, sodium tungstate was used in the development and printing solutions for black-and-white films, although its use has diminished with the advent of digital photography.

Laboratory Uses

Laboratory Reagent: Sodium tungstate is utilized as a laboratory reagent in chemical and analytical processes, serving as a source of tungsten ions or as a reactant in synthetic reactions. It is also used as an indicator in analytical chemistry experiments.
Experimental Biology: Sodium tungstate has a specific application in experimental biology—adding sodium tungstate to the drinking water of mice has been found to inhibit the growth of Enterobacteriaceae, a family of endogenous opportunistic pathogens, in the gut.
Research and Development: Sodium tungstate is used in various research and development activities, including material synthesis, catalytic research, and scientific experiments.

Material Applications

Petroleum Industry and Aerospace Materials: Sodium tungstate is used in manufacturing materials for the petroleum industry and aerospace applications.
Fluxing Agent: Sodium tungstate acts as a fluxing agent, lowering the melting point of materials and improving the processing performance of ceramics and glass.

Water Treatment

Sodium tungstate is employed to remove heavy metals from water by forming insoluble tungstate complexes with heavy metal ions, ensuring their effective removal.

Competitive Inhibitor of Molybdenum

Because tungsten is located directly below molybdenum on the periodic table, they share similar electrochemical properties. Dietary tungsten reduces molybdenum concentrations in tissues.

Medical Applications

Medical Potential: Sodium tungstate has shown potential in medical research due to its properties of combating acne and inhibiting the growth of certain tumor cells.
Embryo Implantation: Sodium tungstate has demonstrated its ability to regulate key molecules during the embryo implantation process. Sodium tungstate has shown positive effects in PCOS-like models, restoring ovulation and fertility. Furthermore, in vitro experiments have proven that sodium tungstate can directly act on the endometrium to increase embryo adhesion. Sodium tungstate has been researched as a potential treatment for infertility, with the code OXO-001. This pill, called OXO-001, aims to directly act on the endometrium to make it more receptive to implanted embryos. This discovery brings hope to patients who have experienced repeated implantation failures during successive rounds of IVF.
Diabetes: Sodium tungstate is a potent anti-diabetic agent when taken orally. In primary cultured hepatocytes, tungstates exhibit insulin-like actions, leading to increased glycogen synthesis and accumulation. The anti-diabetic properties of sodium tungstate have been widely reported. In several animal models of Type 1 and Type 2 diabetes, oral administration of this compound lowers blood glucose, and in most cases, it normalizes blood glucose levels without causing hypoglycemia.

Safety and Toxicity of Sodium Tungstate

Sodium tungstate toxicity

Is sodium tungstate toxic? Sodium tungstate's hazard rating: acute toxicity via oral and respiratory routes (Category 4). The substance and products must be considered harmful.

Sodium Tungstate hazards

Ingestion: The toxicological properties of this substance have not been fully investigated. Swallowing may be harmful. Exposure has caused anorexia, muscle incoordination, weight loss, and death in experiments.
Inhalation: May cause respiratory tract irritation symptoms. The toxicological properties of this substance have not been fully investigated.
Skin: May cause skin sensitization.
Eyes: May cause eye irritation.

Important Information in the Sodium Tungstate MSDS

First Aid Measures

General Advice: Consult a doctor. Show this safety data sheet to the attending physician.
If Inhaled: Is inhaled, move the person to fresh air. If breathing has stopped, perform artificial respiration. Consult a doctor.
In Case of Skin Contact: Wash with soap and plenty of water. Consult a doctor.
In Case of Eye Contact: Rinse thoroughly with plenty of water for at least 15 minutes and consult a doctor.
If Swallowed: Never give anything by mouth to an unconscious person. Rinse mouth with water. Consult a doctor.
Immediate Medical Attention and Special Treatment if Necessary: Basic treatment: Establish a clear airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilation if required. Administer oxygen by non-rebreathing mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary. Monitor for shock and treat if necessary. Prevent seizures and treat if necessary. If the eyes are contaminated, immediately flush the eyes with water. During transport, continue flushing each eye with normal saline. Do not use emetics. If the patient can swallow, has a strong gag reflex, and does not drool, rinse mouth and administer dilution as needed.

Handling and Storage

Safe Handling Precautions: Avoid contact with skin and eyes. Avoid forming dust and aerosols. Avoid exposure – obtain special instructions before use. Provide appropriate exhaust ventilation at places where dust is formed.
Conditions for Safe Storage, Including Any Incompatibilities: Store in a cool place. Keep the container tightly closed in a dry and well-ventilated place.