Calcium aluminium silicate

E number E556CAS 1327-39-5

Chemical structure of Calcium aluminium silicate, from PubChem compound 21881395
Structure from PubChem CID 21881395 (National Library of Medicine, public domain). A depiction of one compound: where a listing covers a family, or a substance has no single structure, this page shows none.

Calcium aluminium silicate is an anticaking agent used in table salt and powdered products. It contributes dietary aluminium, which regulators assess separately from its function in food.

Where it is and isn’t permitted

Status of Calcium aluminium silicate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
Australia and New ZealandFood Standards Australia New ZealandPermitted, with conditions

55 food categories

no numerical limit (good manufacturing practice)

Show every food category
  • 0 Preparations of food additives — GMP
  • 1.1.1 Liquid milk (including buttermilk) — GMPOnly UHT goats milk.
  • 1.1.2 Liquid milk products and flavoured liquid milk — GMP
  • 1.2.2 Fermented milk products and rennetted milk products — GMP
  • 1.3 Condensed milk and evaporated milk — GMP
  • 1.4.1 Cream, reduced cream and light cream — GMPOnly UHT creams and creams receiving equivalent or greater heat treatments.
  • 1.4.2 Cream products (flavoured, whipped, thickened, sour cream etc) — GMP
  • 1.5 Dried milk, milk powder, cream powder — GMP
  • 1.6 Cheese and cheese products — GMP
  • 10.2 Liquid egg products — GMP
  • 10.3 Frozen egg products — GMP
  • 10.4 Dried or heat coagulated egg products — GMP
  • 11.1.1 Rainbow sugar — GMP
  • 11.3.1 Dried honey — GMP
  • 11.4 Tabletop sweeteners — GMP
  • 12.1.1 Salt — GMP
  • 12.1.2 Reduced sodium salt mixture — GMP
  • 12.1.3 Salt substitute — GMP
  • 12.5 Yeast and yeast products — GMP
  • 12.6 Vegetable protein products — GMP
  • 13.3 Formulated meal replacements and formulated supplementary foods — GMP
  • 13.4 Formulated supplementary sports foods — GMP
  • 13.5 Food for special medical purposes — GMP
  • 14.1.1.2 Carbonated, mineralised and soda waters — GMP
  • 14.1.2.1 Fruit and vegetable juices — GMPFor juice separated by other than mechanical means only.
  • 14.1.2.2 Fruit and vegetable juice products — GMP
  • 14.1.3 Water based flavoured drinks — GMP
  • 14.1.4 Formulated Beverages — GMP
  • 14.1.5 Coffee, coffee substitutes, tea, herbal infusions and similar products — GMP
  • 14.2.3 Wine based drinks and reduced alcohol wines — GMP
  • 14.2.4.1 Fruit wine products and vegetable wine products — GMP
  • 14.2.5 Spirits and liqueurs — GMP
  • 14.3 Alcoholic beverages not included in item 14.2 — GMP
  • 2.1 Edible oils essentially free of water — GMP
  • 2.2.1.2 Butter products — GMP
  • 2.2.1.3 Margarine and similar products — GMP
  • 2.2.2 Oil emulsions (<80% oil) — GMP
  • 20 Foods not included in items 0 to 14 — GMP
  • 3 Ice cream and edible ices — GMP
  • 4.1.3 Fruits and vegetables that are peeled, cut, or both peeled and cut — GMP
  • 4.3 Processed fruits and vegetables — GMP
  • 5.1 Chocolate and cocoa products — GMP
  • 5.2 Sugar confectionery — GMP
  • 5.4 Icings and frostings — GMP
  • 6.3 Processed cereal and meal products — GMP
  • 6.4 Flour products (including noodles and pasta) — GMP
  • 7 Breads and bakery products — GMP
  • 8.2 Processed meat, poultry and game products in whole cuts or pieces — GMP
  • 8.3 Processed comminuted meat, poultry and game products, other than products listed in item 8.3.2 — GMP
  • 8.3.2 Sausage and sausage meat containing raw, unprocessed meat — GMP
  • 8.4 Edible casings — GMP
  • 8.5 Animal protein products — GMP
  • 9.2 Processed fish and fish products — GMP
  • 9.3 Semi preserved fish and fish products — GMP
  • 9.4 Fully preserved fish including canned fish products — GMP
Food Standards Code, Schedule 15, S15—5and 54 further provisionsretrieved 2026-10-17
CanadaHealth CanadaNo listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here.
European UnionEuropean Commission / EFSANo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
Great BritainFood Standards Agency / Food Standards ScotlandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
JapanConsumer Affairs AgencyNo listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance.
South KoreaMinistry of Food and Drug SafetyNo listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance.
United StatesFood and Drug AdministrationPermitted21 CFR 182.2122retrieved 2026-10-17
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

How much is permitted

A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.

Australia and New Zealand—55 GMP
United States—1 no quantity stated

No regulator sets a figure for Calcium aluminium silicate. That is not an absence of control: where the listing says quantum satis or good manufacturing practice, the quantity is limited to what the effect requires.

What it is made from

Produced synthetically from silicate, aluminium and calcium sources.

  • Vegan
  • Vegetarian

Compare other additives on the dietary indexes.

CAS registry number
1327-39-5
InChIKey
IQDXNHZDRQHKEF-UHFFFAOYSA-N
PubChem
CID 21881395

How the EU defines it

The legal specification an additive must meet to be sold as this E number in the EU — what it is, how it may be made, and the purity it must reach. From Commission Regulation (EU) No 231/2012.

A specification does not authorise use. This site holds no EU permission for Calcium aluminium silicate in food; see the EU row in the status panel above.

E 556 Calcium aluminium silicate

Synonyms: Calcium aluminosilicate; Calcium silicoaluminate; Aluminium calcium silicate

Assay, identification and purity criteria

Description and assay

Chemical name
Calcium aluminium silicate
Assay
Content on the anhydrous basis: — as SiO₂ not less than 44,0 % and not more than 50,0 % — as Al₂O₃ not less than 3,0 % and not more than 5,0 % — as CaO not less than 32,0 % and not more than 38,0 %
Description
Fine white, free-flowing powder
Note (2)
Period of application: until 31 January 2014.

Identification

Test for calcium
Passes test
Test for aluminium
Passes test
Test for silicate
Passes test

Purity criteria

Loss on drying
Not more than 10,0 % (105 °C, 2 hours)
Loss on ignition
Not less than 14,0 % and not more than 18,0 on the anhydrous basis (1 000 °C, constant weight)
Fluoride
Not more than 50 mg/kg
Arsenic
Not more than 3 mg/kg
Lead
Not more than 5 mg/kg
Mercury
Not more than 1 mg/kg

Commission Regulation (EU) No 231/2012, Annex, E 556

Every name it appears under

37 recorded names. A label may use any of them.

E number

  • E556

CAS registry number

  • 1327-39-5

As it appears in regulation

  • Aluminum calcium silicate
  • Calcium aluminium silicate

Other names

  • ALUMINIUM CALCIUM SILICATE
  • Aluminosilicic acid, calcium salt
  • Aluminum calcium silicate
  • Calcium aluminum silicate
  • Calcium silicoaluminate
  • CCRIS 3933
  • dialuminum;dicalcium;dioxido(oxo)silane
  • IQDXNHZDRQHKEF-UHFFFAOYSA-N
  • Silicic acid, aluminum calcium salt

Hazard reference values

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADInot specified—JECFA1985

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated rather than machine-read, and none has been written for this substance yet.

Common questions

Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.

What is E 556?
E 556 is Calcium aluminium silicate. Calcium aluminium silicate is an anticaking agent used in table salt and powdered products. It contributes dietary aluminium, which regulators assess separately from its function in food.
Is Calcium aluminium silicate banned in Europe?
No. Calcium aluminium silicate does not appear on the EU's list of authorised food additives, which is not the same as being banned: the EU permits an additive only where it has authorised it, and usually the reason for an absence is that no one applied. The EU has made no finding against this substance. It does mean it may not be used as a food additive in the EU today.
Where is Calcium aluminium silicate permitted?
Of the seven regulators this site reads, Australia and New Zealand and the US permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
Is Calcium aluminium silicate vegan?
Yes. Calcium aluminium silicate is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.

Sources for this page

  • anz retrieved 2026-10-17
  • ecfr retrieved 2026-10-17
  • euspecs retrieved 2026-10-18

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable: a JSON record of this additive is given on request —how to ask for access.

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