INS 503(i) is ammonium carbonate, an old-school raising agent traditionally called baker's ammonia or hartshorn. On heating it decomposes into ammonia gas (which evaporates), carbon dioxide (which raises the dough), and water; this gives a particularly crisp, light texture to thin and dry baked goods. It is the leavener behind traditional German Springerle and Lebkuchen cookies, gingerbread biscuits, and some Indian crisp items like khari, matri, and Scandinavian-style crackers. It is generally vegan and is permitted by FSSAI for specified food categories.
Quick Facts
INS Number
503(i)
E-Number
E503(i)
Category
Raising Agent
Veg Status
Vegan
FSSAI Status
Permitted by FSSAI
JECFA ADI
Not specified (1982)
Composition
INS 503(i) is the sub-code for ammonium carbonate. The commercial food-grade product is in practice a mixture of ammonium carbamate, ammonium carbonate, and ammonium hydrogen carbonate in varying proportions (CAS 10361-29-2), all of which decompose to ammonia and carbon dioxide on heating. The sister sub-code INS 503(ii) covers ammonium hydrogen carbonate (ammonium bicarbonate, NH4HCO3) which is the more common modern raising agent and is also known as baker's ammonia. The two sub-codes are often grouped together on labels simply as 'INS 503' or 'baker's ammonia'.
What is INS 503(i)?
INS 503(i) is ammonium carbonate, an old-school raising agent traditionally called baker's ammonia or hartshorn. On heating it decomposes into ammonia gas (which evaporates), carbon dioxide (which raises the dough), and water; this gives a particularly crisp, light texture to thin and dry baked goods. It is the leavener behind traditional German Springerle and Lebkuchen cookies, gingerbread biscuits, and some Indian crisp items like khari, matri, and Scandinavian-style crackers.
Why brands add it
Brands use it because the carbon dioxide release happens fast and clean, giving crackers and thin biscuits a crisper, more porous texture than baking soda alone. Unlike baking soda, ammonium carbonate leaves no residual alkali to taste, because the ammonia evaporates during baking. The trade-off is that it only works in thin, dry, small baked goods: in moist cakes and bread loaves the ammonia stays trapped inside the crumb and tastes bitter, so brands use baking soda or baking powder there instead. The smell of ammonia coming out of the oven during baking is a normal feature, not a sign of a problem; it vents off before the product cools.
Where you'll find it
INS 503(i) commonly shows up on Indian packets in these categories:
traditional German cookies (Springerle, Lebkuchen)
gingerbread and thin spiced cookies
crackers and dry crisp biscuits
khari, matri, and Indian crisp items
wafer biscuits and rusks
pH-control agent in cocoa mass and cocoa powder
Veg or non-veg? - Vegan
Ammonium carbonate is produced industrially by reacting ammonia gas with carbon dioxide and water. No animal product is used in its manufacture. (The historical 'hartshorn' name comes from the medieval source of distilled ammonia, which was the antlers of male deer; that source is purely historical and has not been used in commercial production for centuries.)
FSSAI status and JECFA evaluation
FSSAI: Permitted by FSSAI as a raising agent and acidity regulator under Schedule I of the FSS (Food Products Standards and Food Additives) Regulations 2011 at GMP (Good Manufacturing Practice) levels for specified bakery, confectionery, and cocoa-product categories. The sister sub-code INS 503(ii) ammonium hydrogen carbonate is permitted in the same set of bakery applications.
JECFA: ADI 'not specified' for ammonium carbonate (INS 503(i)), established at the 26th JECFA (1982). 'Not specified' is JECFA's classification at typical use levels: a numerical limit was not considered necessary because ammonium carbonate decomposes during baking (at around 60 degrees Celsius) into ammonia gas, carbon dioxide, and water, and the ammonia evaporates from thin dry baked goods, leaving little residual ammonia in the finished product. The sister sub-code INS 503(ii) ammonium hydrogen carbonate (JECFA Chemical 133) shares the same ADI status.
Also known as
On packets, in recipes, and in conversation, INS 503(i) is also called:
Is INS 503(i) (ammonium carbonate) safe, and is the ammonia smell during baking harmful?+
JECFA gave ammonium carbonate an ADI of 'not specified' at the 26th meeting in 1982, meaning a numerical limit was not considered necessary at typical use levels. The reason the kitchen-smell question matters is that ammonium carbonate decomposes during baking, starting at around 60 degrees Celsius, into three things: ammonia gas (which evaporates out of the oven), carbon dioxide (which raises the dough), and water. The ammonia smell comes off the oven during baking but vents away before the product cools; the finished cookie or cracker contains very little residual ammonia, which is why baker's ammonia has been used for traditional crisp cookies for centuries. The trade-off is that ammonium carbonate only works in thin, dry, small baked goods: in moist cakes and bread loaves the ammonia stays trapped inside and tastes bitter, so brands use baking soda or baking powder there instead. FSSAI permits the use under Schedule I at GMP levels for the specified bakery and confectionery categories.
Is INS 503(i) vegetarian?+
Vegan. Ammonium carbonate is produced industrially by reacting ammonia gas with carbon dioxide and water. No animal product is used in its manufacture. (The historical 'hartshorn' name comes from the medieval source of distilled ammonia, which was the antlers of male deer; that source is purely historical and has not been used in commercial production for centuries.)
Is INS 503(i) permitted by FSSAI?+
Permitted by FSSAI as a raising agent and acidity regulator under Schedule I of the FSS (Food Products Standards and Food Additives) Regulations 2011 at GMP (Good Manufacturing Practice) levels for specified bakery, confectionery, and cocoa-product categories. The sister sub-code INS 503(ii) ammonium hydrogen carbonate is permitted in the same set of bakery applications.
What is INS 503(i) used for?+
Brands use it because the carbon dioxide release happens fast and clean, giving crackers and thin biscuits a crisper, more porous texture than baking soda alone. Unlike baking soda, ammonium carbonate leaves no residual alkali to taste, because the ammonia evaporates during baking. The trade-off is that it only works in thin, dry, small baked goods: in moist cakes and bread loaves the ammonia stays trapped inside the crumb and tastes bitter, so brands use baking soda or baking powder there instead. The smell of ammonia coming out of the oven during baking is a normal feature, not a sign of a problem; it vents off before the product cools.
Is INS 503(i) (also written as E503(i)) the same thing?+
Yes. INS 503(i) (the Codex International Numbering System used by FSSAI) and E503(i) (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 carbonate).
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.