What it is
Disodium phosphate is an inorganic sodium salt of phosphoric acid commonly used at low levels to buffer cosmetic formulas. By helping hold the pH within a target range, it supports the stability and performance of other ingredients in sunscreens and skincare. It is frequently paired with monosodium phosphate or other salts to form a buffer system.
Safety & warnings
Disodium phosphate is generally well tolerated as used in cosmetics, where it appears in small buffering amounts. It is not a fragrance allergen and is not associated with comedogenicity.
Origin & sourcing
It is a synthetically manufactured inorganic salt, typically produced by neutralizing phosphoric acid with a sodium source.
Questions everyone asks
What does disodium phosphate do in skincare?
It is a buffering agent that helps keep the product's pH stable, which supports the consistency and effectiveness of the overall formula.
Is disodium phosphate the same as a fragrance or active ingredient?
No. It is an inorganic salt used in small amounts to control pH and has no scent or sun protection function of its own.