Calcium phosphate
[CAS# 7758-87-4]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Phosphides, metal phosphoric acid, metaphosphoric acid, hypophosphorous acid and pyrophosphate
• Name: Calcium phosphate
• Synonyms: Tricalcium bis(orthophosphate)
• Molecular Formula: Ca3(PO₄)₂
• Molecular Weight: 310.18
• CAS Registry Number: 7758-87-4
• EC Number: 231-840-8
• SMILES: [O-]P(=O)([O-])[O-].[O-]P(=O)([O-])[O-].[Ca+2].[Ca+2].[Ca+2]

Properties

• Density: 3.14 g/mL (20 °C)
• Melting point: 1670 °C
• Water solubility: 0.1 g/L (25 °C)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

The discovery of calcium phosphate dates back to ancient times, when it was recognized that it is present in the bones and teeth of animals and humans. Chemically, calcium phosphate consists of several forms, of which (Ca3(PO4)2) is called tricalcium phosphate, which is widely used in the production of ceramics, fertilizers, and nutritional supplements.

Calcium phosphate, especially hydroxyapatite, is an integral part of bone mineralization and bone structure. It makes up about 70% of bone mass and provides strength and stiffness. Calcium phosphate supplements are used to support bone density and prevent osteoporosis. In dentistry, hydroxyapatite plays a vital role in the formation of enamel and dentin. It helps maintain the integrity of teeth and prevents tooth decay by remineralizing the enamel surface that has been damaged by acid. Calcium phosphate ceramics are used in orthopedic and dental implants due to their biocompatibility and ability to bond with natural bone tissue. They promote bone growth and healing, reduce the risk of implant rejection and promote patient recovery.

Tricalcium phosphate is used as a flux and additive in the ceramic and glass industries. It improves the strength, hardness, and thermal stability of ceramic materials for a variety of applications in construction and manufacturing. Dicalcium phosphate and tricalcium phosphate are important components of fertilizers, providing plants with calcium and phosphorus nutrients they need for growth and development. They can improve soil fertility and increase agricultural crop yields.

Calcium phosphate compounds are used as food additives (E341) to fortify processed foods with calcium and phosphorus. They contribute to bone health and support overall nutritional balance, especially in products such as breakfast cereals, baked goods and dairy alternatives. In food processing, tricalcium phosphate is used as an anti-caking agent to prevent caking and improve the flow of powdered products such as spices, milk powders and baking mixes.

References

1991. The osteogenic potential of culture-expanded rat marrow mesenchymal cells assayed in vivo in calcium phosphate ceramic blocks. Clinical orthopaedics and related research, 262.
DOI: 10.2106/00004623-199173010-00012

1987. Enhanced Enamel F Uptake by Monocalcium Phosphate Monohydrate Gels. Journal of Dental Research, 66(10).
DOI: 10.1177/00220345870660100201

1991. Differential effects of calcium ions and calcium phosphate on cytotoxicity of bile acids. American Journal of Physiology-Gastrointestinal and Liver Physiology, 260(1).
DOI: 10.1152/ajpgi.1991.260.1.g142