Disodium Phosphate
Disodium phosphate
- Role
- A buffering salt that keeps a water-based formula at the intended pH.
- Catalog formulas
- 3
- Type
- Stability
- Verified
- 09.11.2026
What does this ingredient do in an antiperspirant?
An inorganic salt of phosphoric acid, disodium hydrogen orthophosphate. INCI functions: buffering (keeps the product pH stable), anticorrosive for the packaging and fragrance.
Part of a system, not a label in isolation
In the catalogue it appears in water-based roll-ons, usually alongside Sodium Phosphate: together they form a phosphate buffer that holds the pH of the formula. It does not reduce sweating.
In 2021 the CIR reviewed phosphoric acid and 31 of its salts, which serve as buffering agents, corrosion inhibitors, chelating agents and pH adjusters in cosmetics, and concluded that they are safe in the present practices of use and concentration when formulated to be non-irritating.
The CIR conclusion carries a non-irritating formulation condition; tolerance is determined by the finished product.
Not the same as Sodium Phosphate: disodium phosphate carries two sodium atoms per phosphate, while Sodium Phosphate is described by COSMILE as sodium dihydrogen phosphate; they are different salts with separate INCI names.
Products containing Disodium Phosphate
Links are based on the complete published INCI list for the exact product version.
Sources
The conclusions apply to the stated conditions and jurisdictions, not automatically to every concentration or product.
- EU CosIng: Disodium Phosphate Supports: INCI functions, substance identity
- COSMILE Europe (Cosmetics Europe): Disodium Phosphate Supports: INCI functions, substance description
- CIR: Safety Assessment of Phosphoric Acid and Its Salts as Used in Cosmetics (2021) Supports: safety assessment, non-irritating formulation condition