Is E503 halal?

What is E503?

Ammonium carbonate and ammonium hydrogen carbonate (ammonium bicarbonate) are white salts made by reacting ammonia with carbon dioxide and water. Bakers know them as baker's ammonia. When heated they break down completely into gases, which makes thin biscuits light and crisp.

Why it's marked “Generally halal”

They are made from ammonia and carbon dioxide, both produced industrially without animal material. The old name hartshorn comes from deer antlers that were once used to make them, but modern ammonium carbonates are made synthetically. In thin baked goods they leave almost nothing behind.

How to check the label

No special check is needed for this additive. The old name hartshorn in a recipe or on a pack does not mean the product contains antler.

Where you'll find it

• biscuits and cookies
• crackers
• gingerbread
• flat baked goods

Good to know

• E503 covers E503(i) ammonium carbonate and E503(ii) ammonium hydrogen carbonate, also called ammonium bicarbonate.
• JECFA, the FAO/WHO expert committee, gave ammonium carbonate an acceptable daily intake of “not specified”, its category for substances of very low concern.

Similar additives

• E260 Acetic acid Generally halal
• E296 Malic acid Generally halal
• E102 Tartrazine Generally halal
• E110 Sunset Yellow FCF Generally halal
• E124 Ponceau 4R Generally halal
• E129 Allura Red AC Generally halal

See all 89 E-numbers in the halal checker

This list describes where additives usually come from. It isn't a religious ruling, and manufacturers can change their sources. Last reviewed: 14 October 2026.

Sources

1. EU additive specifications, Regulation (EU) No 231/2012 (E 503)
2. JECFA evaluation of ammonium carbonate (INCHEM)

Frequently asked questions