What it is
This is an inorganic potassium salt of phosphoric acid that functions primarily to set and stabilize the pH of a formula. In sunscreens and other skincare it is used at low levels as a buffer, helping keep the product within a target pH range so other ingredients perform consistently. It has no UV-filtering or active conditioning role of its own.
Safety & warnings
Phosphate buffer salts are widely used and generally well tolerated in cosmetics at the low levels needed for pH control. They are not associated with comedogenicity and have low irritation and sensitization potential as used.
Origin & sourcing
Synthetic; an inorganic mineral salt manufactured from phosphoric acid and a potassium source.
Questions everyone asks
What is potassium phosphate used for in skincare?
It is used mainly as a buffering agent and pH adjuster to keep the formula within a stable, intended pH range.
Does potassium phosphate affect the skin directly?
At the low levels used for pH control it has no notable direct skin effect and serves a behind-the-scenes formulation role.