Ammonium Bicarbonate (E 503(ii))

Last reviewed October 19, 2026

In plain words: Ammonium bicarbonate (E 503(ii)), sometimes called baker's ammonia, is a raising agent. When heated it breaks down into ammonia, carbon dioxide and water, which is why it is used in thin, dry biscuits and crackers.

What the evidence review says

Ammonium bicarbonate, or baker's ammonia, is a raising agent used in thin, dry biscuits and crackers. JECFA did not consider a numerical daily intake limit necessary, and FDA affirmed it as GRAS for leavening. The practical issue is a leftover ammonia smell or taste in products that don't bake dry, which is a quality issue rather than a safety finding.

No numerical ADI was considered necessary by JECFA, and FDA affirmed it as GRAS for leavening. The practical issue is leftover ammonia smell or taste if it is used in moist or thick products that do not bake dry. That is a processing and sensory limit, not a carcinogenicity finding in the evaluations located. A completed modern EFSA re-evaluation of E 503 was not located.

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This page is for general education. It is not medical advice and does not replace advice from your doctor, pediatrician, allergist or registered dietitian. Research changes; we review these pages when new evidence or rules come out. Last reviewed October 19, 2026.