Sodium Citrate
Also known as Trisodium citrate, Sodium citrate tribasic, Trisodium 2-hydroxypropane-1,2,3-tricarboxylate, E331
“CIR Expert Panel says: safe as used in cosmetics.”
Sodium Citrate (trisodium citrate, CAS 68-04-2, C6H5Na3O7) is the sodium salt of citric acid, functioning primarily as a pH buffer and mild chelating agent in cosmetic formulations. The CIR Expert Panel assessed sodium citrate together with citric acid, 11 other inorganic citrate salts, and 20 alkyl citrate esters (Fiume, Heldreth, Bergfeld et al., Int J Toxicol 33(2 Suppl):16S-46S, 2014, PMID 24861367) and concluded these ingredients are safe in the present practices of use and concentration. Sodium citrate is explicitly named in the abstract as one of the assessed inorganic citrate salts. The assessment prioritized dermal exposure; both citric acid and sodium citrate are also FDA Generally Recognized As Safe (GRAS) direct food additives (21 CFR 184.1751 for sodium citrate), supporting a long history of safe use, though FDA GRAS status was not independently verified this session and fda is therefore not included in coverage_scope. The QRT row carries Finding=S (Safe) with no Detail column conditions or concentration limits.
Effective pH buffer in the cosmetically relevant pH range (~3.5-6.5), maintaining formulation stability and skin-compatible acidity
Mild chelating agent that sequesters divalent metal ions (Ca2+, Mg2+, Fe2+), improving preservation efficacy and preventing metal-catalyzed oxidation of active ingredients
CIR Expert Panel concluded safe as used in cosmetics (Fiume et al., IJT 2014, PMID 24861367) — same assessment clears citric acid, 12 inorganic citrate salts, and 20 alkyl citrate esters
FDA GRAS status as a direct food additive (21 CFR 184.1751) and EU food additive E331; long history of safe use across food and personal care
Commonly used as a gentler, less acidic alternative to citric acid when a higher pKa buffer system is needed; also used to buffer skin-sensitizing preservative systems
- · INCI 'Sodium Citrate' is generic and covers the trisodium salt (most common), disodium salt, and monosodium salt; all are assessed together under the CIR citrate salts evaluation
As a citrate salt / pH buffer, extremely high concentrations could theoretically lower formulation pH enough to cause mild irritation, but typical cosmetic use as a buffer (0.01-1%) is well below any irritation threshold
CIR Quick Reference Table (12/2017, revised 07/2018) — Sodium Citrate row: Finding=S (Safe), Citation=IJT 33 (S2): 16-46, 2014
“Sodium Citrate | S | | IJT 33 (S2): 16-46, 2014”— QRT-122017revised072018.pdf, p. 119