Body & Beauty / Compounds / Tartaric acid

Tartaric acid on your skin: a safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Tartaric acid (L-tartaric acid; 2,3-dihydroxybutanedioic acid; C₄H₆O₆; E334) is a dihydroxy dicarboxylic acid naturally abundant in grapes and grape products — wine is the primary dietary source (2–10 g/L in wine); it also occurs in tamarind, citrus fruits, and many other plants. Biological occurrence: L-tartaric acid is not a TCA cycle intermediate in mammals (unlike malic or citric acid) and is mostly excreted unchanged in urine after oral ingestion, with limited metabolism — this distinguishes it from most other common food acids. FDA GRAS status: tartaric acid is GRAS as a food acidulant, flavor enhancer, antioxidant synergist, and sequestrant; ADI 0–30 mg/kg bw/day (JECFA). Applications: winemaking (the dominant natural acid in grapes, buffering wine pH), cream of tartar (potassium bitartrate — a baking aid), food acidulant in effervescent tablets, confectionery sour coatings, soft drinks, and pharmaceutical formulations. Wine chemistry significance: tartaric acid's pKa values (2.98 and 4.34) make it the dominant acid governing wine pH; tartrate buffering capacity is critical for wine stability, microbial resistance, and aging potential; potassium tartrate precipitation ('wine diamonds') in chilled wine is a natural tartaric acid phenomenon without safety significance. Acute oral toxicity: very low — oral LD50 in rats approximately 7500 mg/kg; high doses cause osmotic diarrhea (tartaric acid is poorly absorbed). Renal excretion: tartaric acid is primarily renally excreted unchanged — urinary tartrate is a biomarker of grape product consumption. No carcinogen classification.

What is tartaric acid?

The IUPAC name is (2R,3R)-2,3-dihydroxybutanedioic acid.

Also known as: (2R,3R)-2,3-dihydroxybutanedioic acid, L-tartaric acid, L-(+)-Tartaric acid, (2R,3R)-2,3-dihydroxysuccinic acid.

IUPAC name
(2R,3R)-2,3-dihydroxybutanedioic acid
CAS number
87-69-4
Molecular formula
C4H6O6
Molecular weight
150.09 g/mol
SMILES
C(C(C(=O)O)O)(C(=O)O)O
PubChem CID
444305

Risk for people

Low risk

Tartaric acid (L-tartaric acid; 2,3-dihydroxybutanedioic acid; C₄H₆O₆; E334) is a dihydroxy dicarboxylic acid naturally abundant in grapes and grape products — wine is the primary dietary source (2–10 g/L in wine); it also occurs in tamarind, citrus fruits, and many other plants. Biological occurrence: L-tartaric acid is not a TCA cycle intermediate in mammals (unlike malic or citric acid) and is mostly excreted unchanged in urine after oral ingestion, with limited metabolism — this distinguishes it from most other common food acids. FDA GRAS status: tartaric acid is GRAS as a food acidulant, flavor enhancer, antioxidant synergist, and sequestrant; ADI 0–30 mg/kg bw/day (JECFA). Applications: winemaking (the dominant natural acid in grapes, buffering wine pH), cream of tartar (potassium bitartrate — a baking aid), food acidulant in effervescent tablets, confectionery sour coatings, soft drinks, and pharmaceutical formulations. Wine chemistry significance: tartaric acid's pKa values (2.98 and 4.34) make it the dominant acid governing wine pH; tartrate buffering capacity is critical for wine stability, microbial resistance, and aging potential; potassium tartrate precipitation ('wine diamonds') in chilled wine is a natural tartaric acid phenomenon without safety significance. Acute oral toxicity: very low — oral LD50 in rats approximately 7500 mg/kg; high doses cause osmotic diarrhea (tartaric acid is poorly absorbed). Renal excretion: tartaric acid is primarily renally excreted unchanged — urinary tartrate is a biomarker of grape product consumption. No carcinogen classification.

Regulatory consensus

2 regulatory and scientific bodies have classified Tartaric acid. The classifications differ — that's the data.

AgencyYearClassificationNotes
EPA CTX / Genetox—Genotoxicity: positive (Ames: positive, 6 positive / 3 negative reports)
EPA CTX / Genetox—Genotoxicity: positive (Ames: positive, 6 positive / 3 negative reports)

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter tartaric acid

  • Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational Environments — Factories, Warehouses, Transportation vehicles
  • Food — processed food, beverages, candy, baked goods
  • Fragrance — perfume, cologne, scented personal care products, household fragrance products, candles
    Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Tartaric acid:

  • Fragrance-free formulations
    Trade-offs: Consumer preference for scented products
    Relative cost: Lower (ingredient elimination)
  • Essential oil-based fragrances (with disclosure)
    Trade-offs: Natural does not mean safe — many essential oils are skin sensitizers
    Relative cost: 2-5× conventional

Frequently asked questions

What products contain tartaric acid?

Tartaric acid appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments); processed food (Food).

See Tartaric acid in the body app

Look up products containing tartaric acid, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (2)
  1. FDA GRAS: Tartaric Acid (E334) — winemaking dominant acid; cream of tartar; GRAS acidulant; ADI 30 mg/kg; 15-20% GI absorption; renal excretion; sour candy; grape juice natural source (2021) (2021) — regulatory
  2. EFSA ANS Panel: Re-evaluation of Tartaric Acid (E 334) — ADI 30 mg/kg bw/day; osmotic laxative high dose; wine pH buffering; potassium bitartrate; grape pomace recovery; dental erosion; renal excretion biomarker (2020) (2020) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →