Sodium Phosphate
Sodium phosphate
- Role
- A buffering salt that, together with other phosphates, holds the pH of the formula.
- Catalog formulas
- 3
- Type
- Stability
- Verified
- 09.11.2026
What does this ingredient do in an antiperspirant?
An inorganic salt of phosphoric acid; COSMILE describes it as sodium dihydrogen phosphate. INCI functions: buffering, deodorant and anti-seborrhoeic; COSMILE also lists it as a functional fragrance excipient.
Part of a system, not a label in isolation
In the catalogue it appears in water-based roll-ons together with Disodium Phosphate, where it is part of the phosphate buffer. It does not reduce sweating: it is not an aluminium salt.
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 Disodium Phosphate: it is a different sodium salt of phosphoric acid with its own INCI name. The "deodorant" function in CosIng does not mean an antiperspirant effect.
Products containing Sodium 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: Sodium Phosphate Supports: INCI functions, substance identity
- COSMILE Europe (Cosmetics Europe): Sodium 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