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What are the Main Uses of Phosphoric Acid?

The Main Uses of Phosphoric Acid

It is not clear exactly who made phosphoric acid for the first time and when, but historical records date the first invention of phosphorus to German alchemy.

Phosphoric acid, also known as orthophosphoric acid, is a weak mineral acid with the chemical formula H3PO4, which has the highest production of any acid in the world after sulfuric acid. This acid is arguably one of the most widely used acids in the food, cosmetics, pharmaceutical, and especially agricultural industries.

In this article, we have tried to get more familiar with the uses of phosphoric acid.


As you know, fertilizer is an essential food for the growth and health of plants. Phosphoric acid is one of the substances used as fertilizer in agriculture. About 80% of this acid produced in the world is used to make fertilizers. This substance is mainly converted to three types of phosphate salts (triple superphosphate (TSP), diammonium phosphate (DAP), and monoammonium phosphate (MAP), which is used as fertilizer. Today, most agricultural soils face the problem of phosphorus deficiency and thus reduce crop production, while in some areas there is excess phosphorus. Of course, the problem of soil phosphorus deficiency is exacerbated by continuous cultivation and soil erosion.

Therefore, the use of phosphoric acid in agriculture is a great option to strengthen plants and get more products from them.


Phosphoric acid is the most common chemical additive in a variety of foods. There are different amounts of this acid in people’s daily food baskets. The main purpose of adding this mineral acid to foods is to make them taste better. Excessive consumption of this acid reduces the mineral density of the bones; This is why nutritionists warn you to be careful when consuming carbonated beverages and cakes and cookies.


One of the biggest uses of phosphoric acid is in the production of non-alcoholic beverages and cola. The main role of this mineral acid in beverages is to preserve their properties and help them taste better. The cool and desirable taste of the drinks is due to the presence of certain amounts of this acid in these products.

Processed Food:

Pre-packaged breakfasts, beverages, flavored juices, coffee bottles, and processed meats are some of the most important food products made using phosphoric acid. Mutton and chicken are processed with certain solutions of the salts of this acid in order to not only increase the amount of moisture in the meat tissue but also to preserve its original taste and properties. Details of additives to these products are usually written on the packaging. Dicalcium phosphate, hexametaphosphate, sodium phosphate, and tricalcium phosphate salts are examples of these substances.

phosphoric acid in Processed Food

Livestock and Poultry Feed:

Phosphoric acid is also used as an additive in some types of animal and poultry feed. Phosphate salts derived from phosphoric acid are exactly the same chemicals used in the livestock and poultry feed industries. About 5% of global phosphorus production is accounted for by animal feed industries.


In the production of aspirin, phosphoric acid has been introduced as a suitable catalyst due to its high hydrogen ion and lower pollution than other acids. Another use of this acid in medicine is as a cleaning and roughening agent for the tooth surface, especially for the parts of the tooth where dental equipment is used.

Toothpaste is also one of the products offered in the field of dental health, in the production of which dicalcium phosphate, sodium phosphate, calcium pyrophosphate, and tricalcium phosphate are used as tooth polishes. In addition to toothpaste, diammonium phosphate is used to make mouthwashes.

Removing Iron Rust:

Among the various types of acids, phosphoric acid is commonly used to remove rust from metals such as iron, steel, and so on. This acid reacts with the rust and turns a reddish-brown iron (iron oxide) into a black compound (iron phosphate) that is easily eliminated.


As you know, water hardness is one of the most common problems in water resources. Hard water is water that contains a large number of minerals and these minerals often include calcium ions, magnesium, metal cations, and other compounds. One of the problems that hard water can cause is the formation of insoluble deposits with soap and detergents and stains on clothes. Phosphoric acid is used in detergents to soften water and improve the performance of detergents. Phosphorus compounds in detergents form complexes with cations in water and prevent them from reacting with soap and creating annoying deposits.

phosphoric acid in Detergents

Cosmetic Products:

This acid is used as an acidity regulator in the production of a wide range of cosmetic and self-care products, including scrub masks, head and body shampoos, nail polishes, hair dyes, and facial cleansers.


In addition to all the above uses, it can also be mentioned that high purity phosphoric acid is used as a factor in creating electronic circuits in a wide range of electronic devices such as computer screens, smartphones, and LCD TVs.



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5 thoughts on “What are the Main Uses of Phosphoric Acid?

  1. Sarah says:

    Is phosphoric acid also used in dentistry?

    1. china chemicals says:

      Phosphoric acid is widely used in dentistry as a teeth whitener and scaling agent to clean the surface of teeth.

  2. 李娜 says:

    How is phosphoric acid produced?

    1. china chemicals says:

      In general, phosphoric acid is produced in the industry in two main ways: 1) the wet method and 2) the thermal method. In the thermal method, the produced acid has a higher purity and higher concentration, but it needs a lot of energy. Phosphoric acid produced in the wet method is less pure and is suitable for the production of various phosphate fertilizers.

  3. miranda says:

    Why is phosphoric acid in Coca-Cola?

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