E337 · Potassium sodium tartrate
- WHO
- Safe
- FDA
- Safe
- EFSA
- Safe
- FSANZ
- Safe
- Japan
- Safe
- UK FSA
- Safe
- Health Canada
- Safe
What is E337?
Potassium sodium tartrate, also known as Rochelle salt, is a double salt of tartaric acid used in food as a stabilizer and sequestrant, and in some emulsified products to maintain clarity and prevent crystallization. It is also used in medical and laboratory settings (e.g. as a mild laxative and in Fehling's/Benedict's reagents). At food-use levels it is considered safe.
Also appears on labels as: Potassium sodium tartrate, Rochelle salt, Sodium potassium tartrate, Potassium-sodium tartrate, E337, E 337, E-337, Tartrate salt, Potassium sodium tartrate powder, Food grade potassium sodium tartrate, Potassium sodium bitartrate, Kalio natrio tartratas.
What the evidence says
- Generally recognized as safe at typical food levels.
- Larger amounts (as used medicinally) have a laxative effect; not a concern at normal food additive levels.
Frequently asked questions
Is E337 safe?
Our overall verdict for E337 (Potassium sodium tartrate) is “Safe”, based on the most cautious of the major regulators’ positions — FDA: safe; WHO: safe; EFSA: safe; FSANZ: safe; Japan: safe; UK FSA: safe; Health Canada: safe.
Is E337 vegan, halal or gluten-free?
According to our ingredient data for Potassium sodium tartrate — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.
What is E337 and why is it used?
Potassium sodium tartrate, also known as Rochelle salt, is a double salt of tartaric acid used in food as a stabilizer and sequestrant, and in some emulsified products to maintain clarity and prevent crystallization. It is also used in medical and laboratory settings (e.g. as a mild laxative and in Fehling's/Benedict's reagents). At food-use levels it is considered safe.
Does E337 contain allergens?
No known allergens are recorded for Potassium sodium tartrate.
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This page summarises publicly available regulatory assessments and research. It is general information, not medical advice. Sources: EFSA, FDA, WHO and the studies linked above.