Sodium tartrate is a chemical compound, the sodium salt of tartaric acid.

It appears in the form of a white powder.

What it is used for and where

Food

Ingredient listed in the European food additives list as E335, acidity regulator.

Cosmetics

Buffering agent. It is an iingredient that can bring an alkaline or acid solution to a certain pH level and prevent it from changing, in practice a pH stabiliser that can effectively resist instability and pH change.

Safety
Tartaric acid (E 334), sodium tartrates (E 335), potassium tartrates (E 336), sodium potassium tartrate (E 337) and calcium tartrate (E 354) are authorised as food additives according to Regulation (EC) No 1333/2008 on food additives. The Panel established a group ADI for l(+)‐tartaric acid and tartrates (E 334‐337 and E 354) of 240 mg/kg bw per day, expressed as tartaric acid, by applying the total uncertainty factor of 10 to the reference point of 3,100 mg sodium tartrate/kg bw per day (the highest dose tested), that is approximately 2,440 mg tartaric acid/kg bw per day. Accordingly, the current ADI of 30 mg/kg bw per day is withdrawn (1).

Molecular Formula   C₄H₄Na₂O₆
Molecular Weight      194.05
CAS  868-18-8
UNII    QTO9JB4MDD
EC Number  212-773-3
IUPAC  disodium;2,3-dihydroxybutanedioate
InChl=1S/C4H6O6.2Na/c5-1(3(7)8)2(6)4(9)10;;/h1-2,5-6H,(H,7,8)(H,9,10);;/q;2*+1/p-2
InChl Key      HELHAJAZNSDZJO-UHFFFAOYSA-L
SMILES  C(C(C(=O)[O-])O)(C(=O)[O-])O.[Na+].[Na+]

References_____________________________________________________________________

(1) EFSA Panel on Food Additives and Flavourings (FAF); Younes M, Aquilina G, Castle L, Engel KH, Fowler P, Frutos Fernandez MJ, Fürst P, Gürtler R, Gundert-Remy U, Husøy T, Mennes W, Shah R, Waalkens-Berendsen I, Wölfle D, Boon P, Tobback P, Wright M, Aguilera J, Rincon AM, Tard A, Moldeus P. Re-evaluation of l(+)-tartaric acid (E 334), sodium tartrates (E 335), potassium tartrates (E 336), potassium sodium tartrate (E 337) and calcium tartrate (E 354) as food additives. EFSA J. 2020 Mar 11;18(3):e06030. doi: 10.2903/j.efsa.2020.6030.