Base buffering salt – holds the formula's pH in range. Often works with citric acid or a citrate buffer. Without it, pH-sensitive actives (vit C, retinoids, acids) lose stability. Safe.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
Functional buffer. Safety confirmed by CIR.
Sodium Phosphate (Na3PO4) is an inorganic salt of phosphoric acid. In cosmetics it acts as a buffer: maintains the target formula pH together with citric acid or a citrate buffer. Mechanism. Paired with an acidic component it forms an equilibrium that holds pH in the desired range even when stray ions enter the formula. Without a buffer, pH-sensitive actives (vit C, retinoids, AHAs) lose stability quickly. Where applied. Vitamin C serums, acid toners, formulas with retinoids and AHAs. Final-product concentration is a fraction of a percent, near the bottom of the INCI list. Safety. CIR confirmed safety at cosmetic concentrations. Non-sensitizing, non-comedogenic. No systemic absorption. Pregnancy and lactation – safe.
Irritation potential
LowAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Sodium Phosphate is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Sodium Phosphate suits: normal, dry, combination, oily, sensitive.
Base buffering salt – holds the formula's pH in range.
The INCI name is Sodium Phosphate. It may also appear as: Натрия фосфат, Na3PO4.
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