Sodium tetraborate decahydrate
[CAS# 1303-96-4]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Boride, borate and perborate
• Name: Sodium tetraborate decahydrate
• Synonyms: Disodium tetraborate decahydrate; Borax decahydrate
• Molecular Formula: Na₂B₄O₇.10(H₂O)
• Molecular Weight: 381.37
• CAS Registry Number: 1303-96-4
• EC Number: 603-411-9
• SMILES: B1(OB2OB(OB(O1)O2)[O-])[O-].O.O.O.O.O.O.O.O.O.O.[Na+].[Na+]

Properties

• Density: 1.73 g/mL (Expl.)
• Melting point: 75 °C (decomp.) (Expl.)
• Boiling point: 320 °C (Expl.)
• Water solubility: 60 g/L (20 °C) (Expl.)

Safety Data

• Hazard Symbols: GHS07;GHS08 Danger
• Risk Statements: H319-H360
• Safety Statements: P203-P264+P265-P280-P305+P351+P338-P318-P337+P317-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Reproductive toxicity	Repr.	1B	H360
Eye irritation	Eye Irrit.	2	H319
Reproductive toxicity	Repr.	1B	H360FD
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - single exposure	STOT SE	1	H370
Reproductive toxicity	Repr.	2	H361
Specific target organ toxicity - single exposure	STOT SE	3	H335
Reproductive toxicity	Repr.	1A	H360
Reproductive toxicity	Repr.	1B	H360FD

• Transport Information: UN 1458

Discovery and Applications

Sodium tetraborate decahydrate, commonly known as borax, is a naturally occurring mineral with the chemical formula Na₄B₄O₇·10H₂O. It is a colorless crystalline compound that is highly soluble in water and is often used in a variety of applications, ranging from household cleaning products to industrial processes. Borax has been known and used for thousands of years, with its historical significance dating back to ancient civilizations that utilized it in various forms. Today, it continues to be an essential substance in industries such as detergents, glass manufacturing, agriculture, and cosmetics.

The discovery of borax dates back to the ancient civilizations of the Middle East, where it was first extracted from natural deposits in the regions surrounding present-day Iran and Afghanistan. Early references to borax can be found in ancient Chinese, Indian, and Persian texts, where it was used as a flux in metalworking and in the preservation of food. By the 19th century, the mineral's chemical composition was better understood, and it was refined into a more commercially viable product. The industrial use of sodium tetraborate decahydrate expanded during the 1800s, particularly in the production of glass and ceramics, as well as in cleaning products.

One of the most common applications of sodium tetraborate decahydrate is in the manufacture of household and industrial cleaning products. Borax is a powerful alkaline substance that has mild disinfectant and deodorizing properties, making it a popular ingredient in laundry detergents, all-purpose cleaners, and stain removers. Its ability to break down grease, dirt, and oils, while also softening water, makes it an effective cleaning agent for a wide variety of surfaces and fabrics. Borax is often used in combination with other cleaning agents to enhance their performance and provide better cleaning results.

In addition to its use in cleaning products, sodium tetraborate decahydrate plays an essential role in the manufacture of glass and ceramics. In glass production, borax is used as a flux to lower the melting point of silica, which helps improve the workability of glass during the manufacturing process. It also enhances the durability and thermal resistance of the finished product. In ceramics, borax serves as a flux in the glaze formulation, improving the smoothness and gloss of the surface.

Agriculture also benefits from the use of sodium tetraborate decahydrate, particularly as a micronutrient in fertilizers. Boron, an essential trace element for plants, is present in borax, and it plays a critical role in the development of cell walls and the growth of roots and flowers. Borax is often included in fertilizers to address boron deficiencies in soils, particularly in regions where the soil is naturally low in this essential nutrient. However, care must be taken to avoid excessive boron application, as too much boron can be toxic to plants.

Another significant application of sodium tetraborate decahydrate is in the manufacturing of cosmetics and personal care products. Borax is used in formulations for products such as shampoos, body washes, and skin creams, where it functions as an emulsifier and pH buffer. It helps stabilize formulations and improves the consistency of the products. Its mild antiseptic properties also make it useful in some topical creams and ointments, where it can help soothe skin irritations.

Beyond its common applications, sodium tetraborate decahydrate also plays a role in scientific research and certain niche industrial processes. It is used as a reagent in chemical laboratories and is employed in the preparation of certain compounds and reactions. Additionally, borax is used in the production of fiberglass, as well as in the formulation of fire retardants and antifungal treatments.

While sodium tetraborate decahydrate has numerous beneficial applications, it is important to handle the substance with care. Borax is toxic when ingested in large amounts and can cause irritation to the skin, eyes, and respiratory system. Prolonged exposure to high concentrations of borax dust can also lead to more serious health effects. As a result, safety guidelines should be followed when using borax in industrial settings, and consumers should take care to store products containing borax out of reach of children and pets.

In conclusion, sodium tetraborate decahydrate, or borax, is a versatile and valuable compound with a wide range of uses in industries such as cleaning, glass manufacturing, agriculture, and personal care. Its discovery and applications have made it an important chemical for many modern industrial processes. Despite some health and environmental concerns, borax continues to be a crucial substance in various sectors, with ongoing research into its potential uses and safer alternatives.

References

1958. Effects of Electron Bombardment upon Sodium Tetraborate and Boric Acid in an Electron Microscope. Nature, 182(4645).
DOI: 10.1038/1821297a0

2016. Sodium Tetraborate Decahydrate Treatment Reduces Hydrogen Sulfide and the Sulfate-Reducing Bacteria Population of Swine Manure. Journal of Environmental Quality, 45(6).
DOI: 10.2134/jeq2016.06.0219

2022. D-spacing controllable GO membrane intercalated by sodium tetraborate pentahydrate for dye contamination wastewater treatment. Journal of Hazardous Materials, 422.
DOI: 10.1016/j.jhazmat.2021.126939