Sodium Phosphate vs. Trisodium Orthophosphate

What's the Difference?

Sodium Phosphate and Trisodium Orthophosphate are both chemical compounds that contain sodium and phosphate ions. However, they differ in their chemical formulas and properties. Sodium Phosphate refers to a group of compounds that contain varying ratios of sodium and phosphate ions, such as monosodium phosphate (NaH2PO4), disodium phosphate (Na2HPO4), and trisodium phosphate (Na3PO4). On the other hand, Trisodium Orthophosphate specifically refers to the compound Na3PO4, which consists of three sodium ions and one phosphate ion. Trisodium Orthophosphate is commonly used as a food additive and cleaning agent due to its alkaline properties, while Sodium Phosphate compounds have various applications in industries such as food, pharmaceuticals, and water treatment.


AttributeSodium PhosphateTrisodium Orthophosphate
Chemical FormulaNa3PO4Na3PO4
Molar Mass163.94 g/mol163.94 g/mol
Common NameSodium PhosphateTrisodium Orthophosphate
Other NamesTrisodium PhosphateTSP
AppearanceWhite crystalline powderWhite crystalline powder
SolubilitySoluble in waterSoluble in water
UsesFood additive, detergent, water treatmentFood additive, detergent, water treatment
Phosphate Content~18.06%~18.06%

Further Detail


Sodium phosphate and trisodium orthophosphate are two commonly used compounds in various industries and applications. While they both contain sodium and phosphate, they differ in their chemical composition and properties. In this article, we will explore and compare the attributes of sodium phosphate and trisodium orthophosphate, shedding light on their uses, benefits, and potential drawbacks.

Chemical Composition

Sodium phosphate, also known as monosodium phosphate, has the chemical formula NaH2PO4. It consists of one sodium ion (Na+) and one phosphate ion (H2PO4-). On the other hand, trisodium orthophosphate, commonly referred to as sodium phosphate tribasic or TSP, has the chemical formula Na3PO4. It contains three sodium ions (Na+) and one phosphate ion (PO4^3-).

Due to their different chemical compositions, sodium phosphate and trisodium orthophosphate exhibit distinct properties and applications.


Sodium Phosphate:

  • Sodium phosphate is widely used as a food additive, particularly in the meat processing industry. It acts as a pH regulator, emulsifier, and stabilizer in processed meats, enhancing their texture and flavor.
  • It is also utilized in the production of detergents, where it helps to soften water and improve cleaning efficiency.
  • In the medical field, sodium phosphate is used as a laxative to relieve constipation. It works by drawing water into the intestines, softening the stool and promoting bowel movements.
  • Furthermore, sodium phosphate finds applications in water treatment processes, acting as a corrosion inhibitor and scale remover.

Trisodium Orthophosphate:

  • Trisodium orthophosphate is commonly employed as a cleaning agent in various industries, including the automotive and construction sectors. It effectively removes grease, oil, and dirt from surfaces.
  • It is also used as a buffering agent in the formulation of cleaning products, helping to maintain the desired pH level and improve their effectiveness.
  • In addition, trisodium orthophosphate is utilized in the textile industry for dyeing and printing processes, as it helps to fix dyes onto fabrics.
  • Moreover, it finds applications in water treatment plants, where it acts as a sequestering agent, preventing the precipitation of metal ions and improving water quality.


Sodium Phosphate:

  • One of the key benefits of sodium phosphate is its ability to enhance the flavor and texture of processed meats. It helps to retain moisture, resulting in juicier and more tender meat products.
  • As a pH regulator, sodium phosphate contributes to the stability and shelf life of various food products, preventing spoilage and maintaining quality.
  • In the medical field, sodium phosphate provides a fast-acting and effective solution for relieving constipation, promoting regular bowel movements without causing dependency.
  • Furthermore, sodium phosphate's water softening properties make it valuable in detergent formulations, improving cleaning efficiency and reducing the need for excessive detergent usage.

Trisodium Orthophosphate:

  • Trisodium orthophosphate's excellent cleaning capabilities make it a preferred choice in industries where grease and dirt removal is crucial. It helps to maintain cleanliness and hygiene standards.
  • As a buffering agent, trisodium orthophosphate ensures that cleaning products maintain their desired pH levels, optimizing their performance and ensuring effective stain removal.
  • In the textile industry, trisodium orthophosphate plays a vital role in fixing dyes onto fabrics, resulting in vibrant and long-lasting colors.
  • Additionally, its sequestering properties in water treatment processes help to prevent the formation of scale and improve the overall quality of treated water.

Potential Drawbacks

Sodium Phosphate:

  • While sodium phosphate is generally recognized as safe for consumption in regulated amounts, excessive intake can lead to health issues such as electrolyte imbalances and kidney problems.
  • Some individuals may also be sensitive or allergic to sodium phosphate, experiencing adverse reactions such as gastrointestinal discomfort or skin irritation.
  • Furthermore, the use of sodium phosphate in processed meats has raised concerns regarding its potential contribution to high sodium levels in the diet, which can be problematic for individuals with certain health conditions.

Trisodium Orthophosphate:

  • Similar to sodium phosphate, excessive consumption of trisodium orthophosphate can lead to health issues, particularly related to sodium intake and electrolyte imbalances.
  • As a cleaning agent, trisodium orthophosphate may cause skin irritation or respiratory issues if proper safety precautions are not followed during handling and use.
  • Moreover, the sequestering properties of trisodium orthophosphate, while beneficial in water treatment, can have environmental implications if not properly managed, as they can contribute to nutrient pollution in bodies of water.


In summary, sodium phosphate and trisodium orthophosphate are two distinct compounds with different chemical compositions and properties. Sodium phosphate finds applications in the food, detergent, medical, and water treatment industries, offering benefits such as improved texture, pH regulation, and water softening. Trisodium orthophosphate, on the other hand, is commonly used as a cleaning agent, buffering agent, and sequestering agent, providing benefits such as effective grease removal, pH maintenance, and prevention of scale formation. However, both compounds have potential drawbacks, including health concerns related to excessive consumption and environmental implications if not properly managed. It is important to consider these factors when utilizing sodium phosphate or trisodium orthophosphate in various applications, ensuring their safe and responsible use.

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