Disodium Phosphate
Reviewed by Emma · Last updated 14 Aug 2026
“Behind-the-scenes” ingredient commonly used as a buffering agent/pH adjuster
EWG Safety Score
What Is Disodium Phosphate?
Disodium phosphate is a "behind-the-scenes" ingredient that is most commonly used as a buffering agent/pH adjuster in skin care and other cosmetic formulations. It also functions as a corrosion inhibitor to prevent the rusting of metals used in packaging.
As a raw material, disodium phosphate is a hygroscopic powder (meaning it will absorb moisture from air upon exposure but just how much is dependent on the humidity and temperature). Technically it is not a fragrance ingredient (it is odorless in and of itself) yet it can help intensify other fragrance/flavor ingredients if present in a formula.
The 2021 Cosmetic Ingredient Review of disodium phosphate surveyed 280 products containing 0.000054-2.9% of this ingredient, where it was deemed, "safe in the present practices of use and concentration in cosmetics as described in this safety assessment, when formulated to be nonirritating." In another nod to this ingredient's safety, the U.S. FDA has determined that it is generally recognized as safe (GRAS) as a direct food additive.
Clinical Evidence & References
Published Research
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CosmeticsInfo.org, Accessed January 2023, ePublication CosmeticsInfo.org, 2023
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PubChem, Accessed January 2023, ePublication PubChem, 2023
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International Journal of Toxicology, 2021, pages 34S –85S International Journal of Toxicology, 2021
How widely it's used
Regulatory information
Standardised cosmetic-ingredient identifiers used by regulators.
Show identifiers
- INCI Name
- DISODIUM PHOSPHATE
- INN Name
- sodium phosphate, dibasic
- EC Number
- 231-448-7 / -
- Pharmacopoeia Name
- dinatrii phosphas
- Function
- Anticorrosive, Buffering, Masking
From the Clinic
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