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E280PreservativeLow concern
Propionic Acid
In plain words
The short version
A short-chain fatty acid antifungal — the parent of calcium propionate, naturally produced in Swiss cheese.
Why it's green
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Safety profile
JECFA allocated a group ADI 'not limited' to propionic acid and its calcium, potassium and sodium salts (1973, maintained in 1997). Considered safe at food levels. Naturally produced in the human gut by fermentation of dietary fiber. Some anecdotal reports of migraines or irritability at very high industrial exposure.
The detail
First identified in 1844 as a fatty acid degradation product. Naturally produced by Propionibacterium during the fermentation of Swiss cheese — responsible for the characteristic flavor. Industrially produced by ethylene carbonylation.
Used as a free acid in bread and baked goods to inhibit mold, often interchangeable with calcium propionate (E282). Effective antifungal at low concentrations (0.1–0.3%). Does not interfere with yeast activity.
Colorless oily liquid with pungent rancid odor. Miscible with water. Weak acid (pKa 4.87). Most effective as antifungal in protonated form at low pH.
Permitted globally for bakery products. Specific EU max levels by product category.
Sources
- JECFA database — Propionic acid, INS 280 — WHO / FAO JECFA, 1997. JECFA group ADI 'not limited' for propionic acid and its salts
- 21 CFR 184.1081 — Propionic acid (GRAS), eCFR as of 1 Oct 2026 — US eCFR (National Archives / GPO), 2026. US: GRAS as antimicrobial under GMP
- Regulation (EC) No 1333/2008 on food additives, consolidated text (18 Aug 2026), Annex II Part E — EUR-Lex (European Union), 2026. EU maximum levels per bakery category
Checked against these sources on .
Educational information only. Not medical, dietary or veterinary advice. Spotted an error? Tell us.