Barium sulfate
[CAS# 7727-43-7]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Metal sulfides and sulfates
• Name: Barium sulfate
• Synonyms: Barium(2+) sulfate
• Molecular Formula: BaSO₄
• Molecular Weight: 233.39
• CAS Registry Number: 7727-43-7
• EC Number: 231-784-4
• SMILES: [O-]S(=O)(=O)[O-].[Ba+2]

Properties

• Density: 4.5 g/mL (Expl.)
• Melting point: 1580 °C decomp.) (Expl.)
• Refraction index: 1.64 (Expl.)
• Water solubility: 0.0022 g/L (50 °C) (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Safety Statements: S24/25

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	2	H371
Carcinogenicity	Carc.	1A	H350
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

Discovery and Applications

Barium sulfate, a chemical compound with the formula BaSO₄, is a naturally occurring mineral that plays a significant role in various industrial applications. It is commonly found as the mineral barite, which has been used for centuries due to its unique properties. The compound was first isolated in the 17th century, and its name is derived from the Greek word "barys," meaning heavy, referring to its high density. Barium sulfate is an odorless, white, crystalline powder that is insoluble in water but highly stable under normal conditions, making it a valuable material in a range of industries.

One of the primary uses of barium sulfate is in the oil and gas industry, where it is used as a weighting agent in drilling fluids. In drilling operations, it is important to control the pressure in the borehole, and barium sulfate helps achieve this by increasing the density of the drilling mud. This helps prevent blowouts by balancing the pressure between the well and the surrounding formation. The high density of barium sulfate makes it ideal for this purpose, as it can withstand high pressures while maintaining stability. Barium sulfate’s effectiveness in this application is also enhanced by its ability to remain inert under harsh drilling conditions, ensuring that it does not react with other substances in the drilling mud.

In addition to its role in the oil and gas industry, barium sulfate is also widely used as a contrast medium in medical imaging, particularly in X-ray and CT scans. When ingested or injected, barium sulfate absorbs X-rays and appears white on X-ray films, providing a clear outline of the organs and structures being examined. This makes it invaluable in diagnosing various gastrointestinal conditions, such as ulcers, tumors, or blockages in the esophagus, stomach, and intestines. The contrast-enhancing properties of barium sulfate allow for detailed imaging, aiding physicians in accurate diagnosis and treatment planning.

Barium sulfate also finds application in the manufacturing of paints and coatings. Due to its excellent opacity and ability to reflect light, it is commonly used as a filler and white pigment in the production of paints, plastics, and rubber. Barium sulfate improves the brightness and opacity of these products, making them more visually appealing and durable. In paints, it provides a smooth finish and helps the paint cover surfaces more effectively. It is also used in the production of specialty coatings, such as those used in automotive and aerospace industries, where its high density and resistance to heat contribute to the durability of the final product.

In the cosmetic and pharmaceutical industries, barium sulfate is used as an inactive ingredient in products such as makeup, lotions, and tablets. It is often employed as a filler in tablets and capsules, where it adds bulk and improves the texture and consistency of the product. Its safety profile and inert nature make it suitable for use in personal care products. Moreover, its high opacity ensures that it can be used to create a uniform appearance in various cosmetic formulations.

The use of barium sulfate is also prominent in the paper industry, where it is used as a coating pigment to improve the quality of paper products. It enhances the whiteness and smoothness of paper, making it suitable for high-quality printing and publishing. In addition, barium sulfate is used in certain glass manufacturing processes to improve the clarity and quality of glass products.

Despite its many uses, barium sulfate must be handled with caution. While it is generally considered safe in many applications, exposure to barium compounds in excessive amounts can be toxic, particularly when inhaled as dust or ingested in large quantities. For this reason, safety guidelines are strictly followed when handling barium sulfate in industrial and medical settings.

Barium sulfate’s versatile properties, including its high density, inertness, and opacity, make it an essential compound in industries ranging from oil and gas to healthcare and manufacturing. Its continued use in medical imaging, industrial applications, and various products underscores its importance as a vital chemical substance in modern society.

References

2024. New Strategy for Selection of Best Water Chemistry of Injected Fluid During Water Flooding to Mitigate Scaling Problem. Arabian Journal for Science and Engineering, 49(12).
DOI: 10.1007/s13369-024-09846-1

2024. Production of heterogenous bone radiopacity phantom using 3D printing. Physical and Engineering Sciences in Medicine, 47(4).
DOI: 10.1007/s13246-024-01500-2

2024. Highly Selective Ag-Ca@CuO Nanocomposite-Based Sensor for Trace-Level Cr (VI) Detection in Water. Water, Air, & Soil Pollution, 235(12).
DOI: 10.1007/s11270-024-07662-9