Disodium phosphate

Disodium phosphate (CAS 7558-79-4), also known as DSP and classified as E339(ii) in food applications, is an inorganic phosphate salt used across food, pharmaceutical, and industrial water treatment sectors.

Where is Disodium phosphate used?

• Food manufacturing: emulsifying salt and pH regulator in processed cheese, instant noodles and canned products
• Pharmaceuticals: buffer solutions for injectable formulations, oral liquids and tablet coatings
• Water treatment: prevents scale and corrosion, protects boiler systems and cooling towers by sequestering calcium and magnesium ions
• Ceramics and detergents: dispersing and deflocculating agent
• It buffers pH, sequesters metal ions and stabilizes formulations where acidity control is critical.
• Used in condensed milk.
• In meat products it acts as a humectant and extends shelf life.
• Used together with trisodium phosphate in steam boiler applications to delay calcium scale formation.

Typical specification

• Minimum purity of 98% on a dry basis.
• A 1% solution has a pH between 8.4 and 9.6.
• The anhydrous form is ideal for food and detergent applications, while the hydrated form is ideal for water treatment.
• Anhydrous form has a solubility of about 70 g per 100 mL in water at 25°C.
• Available in different hydrate forms: anhydrous, dihydrate, heptahydrate and dodecahydrate.

Regulatory status

• Pharmacotherapeutic group: osmotic laxative, ATC code: A06A5.

Storage, packaging and handling

• Should be stored in cool and dry conditions, with packaging kept closed to prevent contact with air due to its hygroscopic nature.

Frequently asked questions about Disodium phosphate

In which food products does disodium phosphate improve consistency and structural stability?

In products such as ice cream and jelly it increases consistency and structural stability.

Is disodium phosphate used in instant pudding?

Yes, disodium phosphate is used in instant pudding.

What are the solubility characteristics of disodium phosphate anhydrous?

Disodium phosphate anhydrous is insoluble in alcohol and organic solvents.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.