INS 503 is ammonium bicarbonate, an old-school baking ammonia that releases carbon dioxide and ammonia gas when heated. It is used in flat, dry baked goods like crackers, biscuits, and matri where the moisture is low enough for the ammonia to escape cleanly. It is generally vegan and is permitted by FSSAI for specified food categories.
Quick Facts
INS Number
503
E-Number
E503
Category
Raising Agent
Veg Status
Vegan
FSSAI Status
Permitted by FSSAI
JECFA ADI
Not specified
Chemical Name
ammonium hydrogen carbonate (NH4HCO3)
What is INS 503?
INS 503 is ammonium bicarbonate, an old-school baking ammonia that releases carbon dioxide and ammonia gas when heated. It is used in flat, dry baked goods like crackers, biscuits, and matri where the moisture is low enough for the ammonia to escape cleanly.
Why brands add it
Brands use it because it gives crackers and thin biscuits a crisper, lighter texture than baking soda alone. It only works for thin, dry products: in moist cakes the ammonia would stay trapped and taste bitter, so you will not see it on cake or bread packs.
Where you'll find it
INS 503 commonly shows up on Indian packets in these categories:
crackers and matri
khari biscuits
thin and crispy biscuits
rusk and toasts
wafer biscuits
Veg or non-veg? - Vegan
Ammonium bicarbonate is produced by reacting ammonia, carbon dioxide, and water. No animal product is used in its manufacture.
FSSAI status and JECFA evaluation
FSSAI: Permitted by FSSAI as a raising agent under Schedule I of the FSS (Food Products Standards and Food Additives) Regulations 2011 for specified bakery and confectionery categories.
JECFA: ADI 'not specified' for ammonium carbonates, the modern equivalent meaning normal dietary intake is not a hazard. The compound decomposes during baking to ammonia and carbon dioxide that vent off, so very little remains in the final product.
Also known as
On packets, in recipes, and in conversation, INS 503 is also called:
Vegan. Ammonium bicarbonate is produced by reacting ammonia, carbon dioxide, and water. No animal product is used in its manufacture.
Is INS 503 permitted by FSSAI?+
Permitted by FSSAI as a raising agent under Schedule I of the FSS (Food Products Standards and Food Additives) Regulations 2011 for specified bakery and confectionery categories.
What is INS 503 used for?+
Brands use it because it gives crackers and thin biscuits a crisper, lighter texture than baking soda alone. It only works for thin, dry products: in moist cakes the ammonia would stay trapped and taste bitter, so you will not see it on cake or bread packs.
Is INS 503 (also written as E503) the same thing?+
Yes. INS 503 (the Codex International Numbering System used by FSSAI) and E503 (the European E-number system) refer to the same compound. The digits are identical for almost all common additives. Indian packets may show either form, or the common name (ammonium bicarbonate).
This page summarises FSSAI's permission status and JECFA's scientific evaluation. It is not medical or dietary advice. Manufacturer ingredient sourcing can vary, especially for source-dependent additives - the Indian veg/non-veg dot logo on the pack is the brand's declaration. For health decisions, consult a doctor or registered dietitian.