My diet:

E503 Ammonium carbonate

E503Acidity regulatorsOrigin: Lab-made
Get a personal answer

Pick your family’s diets in the bar above.

Every diet

VeganYes
Gluten-freeYes
HalalYes
KosherYes
KetoYes
Low-FODMAPYes
The short answer
Ammonium carbonate (E503) is a traditional leavening agent that makes thin cookies and crackers crisp. It breaks down into gas in the oven, so little of it stays in the finished food.
Generally safe

Fine for most people at normal amounts.

E-numberE503
Comes fromLab-made
What it doesAcidity regulators
Glycemic index—
Daily limitNot set
Also calledE503, Baker's ammonia

Rules by country

🇺🇸 US FDAApproved
🇪🇺 European UnionApproved
🇨🇦 Health CanadaApproved
CaliforniaNo extra rules

Permitted in the US, EU and Canada as a leavening agent, mainly for thin, crisp baked goods like crackers and cookies. Most of it leaves as gas in the oven.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

When heated, ammonium carbonate turns into ammonia, carbon dioxide and water. Those gases puff up the dough and then escape, which is why bakers use it for thin products where the gas can leave the oven.

Where it comes from: Made by reacting ammonia with carbon dioxide. Heat breaks it down into ammonia, carbon dioxide and water, so very little of it stays in the finished food.

Why it’s in food

  • Lifts thin crackers and cookies
  • Makes crisp, light wafers
  • Works fast in the oven
  • Leaves little flavor when baked properly

Often found in

CrackersGinger snapsShortbreadWafer biscuitsAnimal crackers

Also listed as: E503, Baker's ammonia, Hartshorn

Health & gut impact

Ammonia smellConcern

Baking drives off almost all of the ammonia. A strong smell in a finished cookie usually means it was under-baked or the leavener was used in too thick a product.

FDA 21 CFR 184.1138

What can I use instead?

Baking soda (E500)

Ratio: About 1:1 by weight, with an acid to react

Best for: Cookies and crackers where you can add an acid

Baking powder

Ratio: About twice the weight

Best for: Home baking

Related

More acidity regulators:

Acetic acid E260Acetic acid (E260) is the acid that makes vinegar sour. Diluted in food it is considered safe. The hazard is the concentrated factory form, not a splash of vinegar.Generally safeCalcium carbonate E170Calcium carbonate (E170) is ground limestone, the same calcium found in antacids. It adds calcium to plant milks and flour and is very safe.Generally safeCalcium chloride E509Calcium chloride (E509) is a salty calcium salt that firms tofu, cheese curds and pickles. It is considered safe at food doses. Too much tastes bitter, which is why recipes use a little.Generally safeCalcium citrates E333Calcium citrates (E333) are a calcium salt of citric acid. Food makers use them to firm produce and buffer acidity, and the same salt is a common calcium supplement. They are considered safe.Generally safe

Common questions

Is ammonium carbonate safe to eat?

Yes, in baked goods. It is approved in the US, EU and Canada, and it breaks down into gases during baking.

Why do some crackers smell of ammonia?

Usually the product was not baked long enough, so some ammonia remains. Thorough baking removes it.

Is Ammonium carbonate safe?

Generally safe (88/100). Permitted in the US, EU and Canada as a leavening agent, mainly for thin, crisp baked goods like crackers and cookies. Most of it leaves as gas in the oven.

Spotted a mistake on this page? Report it ›

Scientific sources & regulatory citations
  • 21 CFR 184.1138 (US FDA)
  • EFSA OpenFoodTox: E503
  • FDA 21 CFR 184.1138

INS 503 · CAS 10361-29-2