Potassium phosphate is a chemical compound, the potassium salt of phosphoric acid.

The name describes the structure of the molecule:

Potassium is an essential chemical element for many bodily functions, including regulating blood pressure and muscle and nerve function.

Phosphate is an important functional group in biology and chemistry, essential for energy production in cells and for the structure of biological molecules like DNA.

Description of Raw Materials and Their Functions

Phosphate, used as the base for the formation of potassium phosphate. It is an important source of phosphorus in many applications.

Potassium, used to neutralize phosphoric acid and form the potassium salt. It enhances the solubility and chemical properties of the compound.

Industrial Chemical Synthesis of Potassium Phosphate

• Preparation. The synthesis begins with the reaction of phosphoric acid with a potassium base, such as potassium hydroxide.
• Neutralization. During this reaction, phosphoric acid is neutralized by potassium, forming potassium phosphate.
• Reaction Control. The reaction is monitored to ensure that the ratio of phosphoric acid to potassium is correct and that the desired salt is formed.
• Purification. After the reaction, the product is purified to remove impurities and by-products.
• Quality Control and Packaging. Potassium phosphate undergoes quality checks.

It appears as a crystalline powder.

What it is used for and where

Potassium phosphate is an inorganic compound consisting of potassium ions (K⁺) and phosphate (PO₄³⁻). It is commonly used in medicine, food, and personal care products as a pH regulator, buffering agent, and source of potassium. In food products, it helps maintain product stability and quality, while in medicine, it is used to correct electrolyte imbalances.

Food

In the food industry, it is used as an acidity regulator and to prevent the formation of lumps in baked goods.

An ingredient included in the list of European food additives as E340 acidity regulator and chelating agent with the following specifications :

• E340 (i) Monopotassium phosphate   CAS   7778-77-0
• E340 (ii) Dipotassium phosphate   CAS   7758-11-4 
• E340 (iii) Tripotassium phosphate   CAS   7778-53-2 

Medical

Potassium phosphate is widely used to control hypophosphatemia, i.e. phosphate deficiency in the blood, and to prevent the formation of kidney stones.

Cosmetics

Antibacterial and to prevent the formation of lumps.

Buffering agent. It is an iingredient that can bring an alkaline or acid solution to a certain pH level and prevent it from changing, in practice a pH stabiliser that can effectively resist instability and pH change.

Other uses

As an industrial product, it is made from phosphoric acid and has numerous applications in various sectors:

• agricultural fertilisers
• forestry
• fishing

Commercial applications:

Supplements and Nutrition. Employed in supplements as a source of potassium, an essential mineral for muscle and nerve function.

Pharmaceutical Industry. Used in some pharmaceutical formulations, especially in electrolyte balance solutions and intravenous preparations.

Plant Care Products. Used as a fertilizer or supplement to provide potassium, an essential nutrient for plant growth.

Safety

The Panel on Food Additives and Flavourings added to Food (FAF) provided a scientific opinion re-evaluating the safety of phosphates (E 338–341, E 343, E 450–452) as food additives. The Panel considered that (1). The Panel considered that phosphates have low acute oral toxicity and there is no concern regarding genotoxicity and carcinogenicity. The Panel calculated a group Acceptable Daily Intake (ADI) for phosphates expressed as phosphorus of 40 mg/kg body weight (bw) per day and concluded that this ADI is protective for the human population (1).

Potassium phosphate studies

• Molecular Formula: K₃O₄P   K₃PO₄
• Molecular Weight: 212.265 g/mol
• UNII: 16D59922JU
• CAS: 7778-53-2    14887-42-4  16068-46-5  44042-47-9  1017687-06-7  1269628-80-9  1608125-41-2  2139271-06-8
• EC Number: 231-907-1  238-961-5  240-213-8  920-994-8
• PubChem Substance ID 57654540
• MDL number MFCD00036295

Synonyms:

• Tripotassium phosphate
• E340
• tri-Potassium orthophosphate
• Potassium phosphate, anhydrous
• Tripotassium phosphate,anhydrous
• Potassium phosphate tribasic anhydrous
• phosphoric acid potassium salt
• Phosphate buffer
• potassiumphosphate
• potasium phosphate
• tri potassium phosphate
• tri-potassium phosphate
• Tripotassium phosphate|
• tris-potassium phosphate
• potassium phophate
• potassium phoshate
• potassium-phosphate
• Tripotasium phosphate
• tripotassium,phosphate
• tripotassiurn phosphate
• Potassium phosphate tribasic
• Tripotassium orthophosphate
• Phosphoric acid, tripotassium salt
• Potassium orthophosphate
• Caswell No. 700A
• Phosphoric acid, potassium salt
• Potassium phosphate, tribasic

References_______________________________________________________________________

(1) EFSA Panel on Food Additives and Flavourings (FAF); Younes M, Aquilina G, Castle L, Engel KH, Fowler P, Frutos Fernandez MJ, Fürst P, Gürtler R, Husøy T, Mennes W, Moldeus P, Oskarsson A, Shah R, Waalkens-Berendsen I, Wölfle D, Aggett P, Cupisti A, Fortes C, Kuhnle G, Lillegaard IT, Scotter M, Giarola A, Rincon A, Tard A, Gundert-Remy U. Re-evaluation of phosphoric acid-phosphates - di-, tri- and polyphosphates (E 338-341, E 343, E 450-452) as food additives and the safety of proposed extension of use. EFSA J. 2019 Jun 12;17(6):e05674. doi: 10.2903/j.efsa.2019.5674.