Calcium silicate
10101-39-0 · Calcium monosilicate · Calcium silicate · E552 · 552 · Calcium;dioxido(oxo)silane · Calcium silicate · Calcium silicate · Calciumsilicaat · Calciumsilicat · Kalcija silikāts · Kalcijev silikat · Kalcio silikatas · Kalcium-szilikát · Kalciumsilikat · Kalsiumsilikaatti · Kaltsiumsilikaat · Krzemian wapnia · Křemičitan vápenatý · Silicat de calciu · Silicate de calcium · Silicato cálcico · Silicato de cálcio · Silicato di calcio · Silikat tal-kalċju · Πυριτικό ασβέστιο · Калциев силикатE number E552INS 552CAS 10101-39-0
Listed as an anticaking agent by Canada, Codex and the US.
Listed as anticaking agents (CA, US, Codex) · flavour enhancers (US) · flavouring agents and adjuvants (US) · carriers (CA) · formulation aids (US) · lubricants and release agents (US)
- Canada: Anticaking agent — Health Canada, List of Permitted Anticaking Agents (List 1)
- United States: Anticaking agent or free-flow agent — FDA, Substances Added to Food: CALCIUM SILICATE
- Codex Alimentarius: Anticaking agent — CXS 192-1995 Table One, INS 552
- United States: Flavor enhancer — FDA, Substances Added to Food: CALCIUM SILICATE
- United States: Flavoring agent or adjuvant — FDA, Substances Added to Food: CALCIUM SILICATE
- Canada: Carrier — Health Canada, List of Permitted Food Additives with Other Purposes of Use (List 8)
- United States: Formulation aid — FDA, Substances Added to Food: CALCIUM SILICATE
- United States: Lubricant or release agent — FDA, Substances Added to Food: CALCIUM SILICATE
Calcium silicate is an anticaking agent, used in table salt, baking powder and powdered mixes. It absorbs many times its weight in moisture, which is how it keeps a powder flowing.
Where it is and isn’t permitted
| Jurisdiction | Status | Scope and limits | Citation |
|---|---|---|---|
| Australia and New Zealand | Permitted, with conditions | 55 food categories no numerical limit (good manufacturing practice) Show every food category
| Food Standards Code, Schedule 15, S15—5and 54 further provisionsretrieved 2026-10-17 |
| Canada | Permitted, with conditions | highest permitted level 5 % 10 permitted uses Show every permitted use
| Health Canadaand 9 further provisionsretrieved 2026-10-17 |
| European Union | Permitted, with conditions | 17 food categories highest permitted level 30,000 mg/kg Show every food category
| Regulation (EC) No 1333/2008, Annex IIand 16 further provisionsretrieved 2026-10-18 |
| Great Britain | Permitted, with conditions | 18 food categories highest permitted level 30,000 mg/kg or mg/l Show every food category
| Assimilated Regulation (EC) No 1333/2008and 17 further provisionsretrieved 2026-10-18 |
| Japan | Permitted, with conditions | Designated additive: Appended Table 1, item 140, ケイ酸カルシウム (“Calcium Silicate” in the unofficial English translation). …Designated additive: Appended Table 1, item 140, ケイ酸カルシウム (“Calcium Silicate” in the unofficial English translation). Standards for use — Specifications and Standards for Foods, Food Additives, etc. (MHW Notification No. 370 of 1959), Part II (Food Additives), F (Standards for use), entry ケイ酸カルシウム: (1) [must not be used in the foods stated] “ケイ酸カルシウムは、母乳代替食品及び離乳食品に使用してはならない。” (2) [sets maximum levels of use for the foods stated; sets a combined limit where it is used together with the additives stated] “ケイ酸カルシウムの使用量は、食品(特定保健用食品たるカプセル及び錠剤並びに栄養機能食品たるカプセル及び錠剤を除く。以下この目において同じ。)の2.0%以下でなければならない。また、微粒二酸化ケイ素と併用する場合は、それぞれの使用量の和が食品の2.0%以下でなければならない。” The Japanese is the standard as published. There is no official English translation of the Notification; the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications for this additive, in the same Notification, are not imported and are not shown here; nor are the general rules in F 添加物一般, which apply to every additive. | Regulations for Enforcement of the Food Sanitation Act (MHW Ordinance No. 23 of 1948), Appended Table 1retrieved 2026-10-18 |
| South Korea | Permitted, with conditions | Designated food additive: Standards and Specifications for Food Additives, Part III, 1. …Designated food additive: Standards and Specifications for Food Additives, Part III, 1. 일반식품첨가물 (general food additives), 규산칼슘 (“Calcium Silicate”, the English the Code prints beside it); the Code marks it as also usable as a processing aid; 2. 가공보조제 (processing aids), 규산칼슘 (“Calcium Silicate”, the English the Code prints beside it); the Code marks it as also usable as a general food additive. Main use (주용도) of 규산칼슘: 고결방지제. Standard for use (사용기준) of 규산칼슘: (1) [may be used only in the foods listed; sets a limit on the amount used] “규산칼슘은 아래의 식품에 한하여 사용하여야 한다. 규산칼슘의 사용량은 1. 가공유크림(자동판매기용 분말 제품에 한함) : 1% 이하(이산화규소 또는 규산마그네슘과 병용할 때에는 각각의 사용량의 합계가 1% 이하) 2. 분유류(자동판매기용에 한함) : 1% 이하(이산화규소 또는 규산마그네슘과 병용할 때에는 각각의 사용량의 합계가 1% 이하) 3. 식염 : 2% 이하(이산화규소 또는 규산마그네슘과 병용할 때에는 각각의 사용량의 합계가 2% 이하) 4. 건강기능식품(정제, 캡슐 제품에 한함)” Main use (주용도) of 규산칼슘: 여과보조제. Standard for use (사용기준) of 규산칼슘: (1) [must be removed before the final food is complete] “규산칼슘은 최종식품의 완성 전에 제거하여야 한다.” The Korean is the standard as published. There is no official English translation of the current Code (the English version on MFDS’s website is the 2020 edition and has no legal effect); the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications (Part IV) are not imported, nor are the general standards in Part II, which apply to every additive. | Standards and Specifications for Food Additives (식품첨가물의 기준 및 규격), MFDS Notification, Part III (Standards for use, by item)retrieved 2026-10-18 |
| United States | Permitted, with conditions | 21 CFR 172.410and 1 further provisionretrieved 2026-10-17 | |
| Codex Alimentarius | Permitted, with conditions | 8 food categories highest permitted level 15,000 mg/kg Show every food category and its notes
| CXS 192-1995 Table Three, INS 552and 8 further provisionsretrieved 2026-09-07 |
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 |
|---|---|---|
| Canada | 10,000 mg/kg – 50,000 mg/kg | 3 numeric limit, 3 GMP, 4 no quantity stated |
| European Union | 10,000 mg/kg – 30,000 mg/kg | 11 numeric limit, 6 quantum satis |
| Great Britain | 10,000 mg/kg – 30,000 mg/kg | 10 numeric limit, 2 several limits, 6 quantum satis |
| Japan | — | 1 no quantity stated |
| South Korea | — | 1 no quantity stated |
| United States | — | 2 no quantity stated |
| Codex Alimentarius | 10,000 mg/kg – 15,000 mg/kg | 2 numeric limit, 7 GMP |
What it is made from
Produced synthetically from lime and silica, or prepared from natural silicate minerals.
- Vegan
- Vegetarian
Compare other additives on the dietary indexes.
- CAS registry number
- 10101-39-0
The two specifications, compared
The European Union sets identity and purity by regulation; JECFA publishes its own through FAO, advisory until a country adopts it. Both documents are below in full. These are the parameters each puts a number on.
| Parameter | European Union | JECFA |
|---|---|---|
| Assay | stated in prose | no less than 50 % |
| Loss on drying | no more than 10 % | no more than 10 % |
| Lead | no more than 2 mg/kg | — |
| Arsenic | no more than 3 mg/kg | — |
| Mercury | no more than 1 mg/kg | — |
The two documents state the same figures for every parameter compared here.
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.
E 552 Calcium silicate
Calcium silicate is a hydrous or anhydrous silicate with varying proportions of CaO and SiO₂. The product should be free of asbestos.
Assay, identification and purity criteria
Description and assay
- Einecs
- 215-710-8
- Chemical name
- Calcium silicate
- Assay
- Content on the anhydrous basis: — as SiO₂ not less than 50 % and not more than 95 % — as CaO not less than 3 % and not more than 35 %
- Description
- White to off-white free-flowing powder that remains so after absorbing relatively large amounts of water or other liquids
Identification
- Test for silicate
- Passes test
- Test for calcium
- Passes test
- Gel formation
- Forms a gel with mineral acids
Purity criteria
- Loss on drying
- Not more than 10 % (105 °C, 2 hours)
- Loss on ignition
- Not less than 5 % and not more than 14 % (1 000 °C, constant weight)
- Sodium
- Not more than 3 %
- Fluoride
- Not more than 50 mg/kg
- Arsenic
- Not more than 3 mg/kg
- Lead
- Not more than 2 mg/kg
- Mercury
- Not more than 1 mg/kg
How JECFA defines it
The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.
INS 552 Calcium Silicate
Calcium silicate is an inorganic substance that is a hydrous or anhydrous substance with varying proportions of calcium as calcium oxide, and silicon as silicon dioxide. It is prepared by various reactions between siliceous material (e.g. diatomaceous earth) and calcium compounds (e.g. lime, calcium hydroxide).
Synonyms: Silicic acid, calcium salt; calcium silicon oxide; INS No. 552
Assay, identification and purity criteria
Description and assay
- Specification history
- Specifications prepared at the 80 th JECFA (2015) and published in FAO JECFA Monographs 17 (2015), superseding tentative specifications prepared at the 77th JECFA (2013), published in FAO JECFA Monographs 14 (2013). An ADI 'not specified' for silicon dioxide and certain silicates including calcium silicate was established at the 29th JECFA (1985)
- Chemical names
- Calcium silicate
- C.A.S. number
- 1344-95-2
- Chemical formula
- xCaO · ySiO2 · zH2O
- Assay
- Not less than 50% and not more than 95% of silicon dioxide (SiO2) and not less than 3% and not more than 35% of calcium oxide (CaO), calculated on the ignited basis.
- DESCRIPTION
- Very fine, white or off-white powder with low bulk density and high physical water absorption
- FUNCTIONAL USES
- Anticaking agent, processing aid (filtering aid)
- METHOD OF ASSAY
- Weigh about 0.5 g of the sample to the nearest 0.1 mg, in a platinum or nickel crucible, add 5 g potassium hydroxide and 2 g boric acid. Mix and melt completely using a torch burner and allow to stand at room temperature. Place the reaction product along with crucible into 150 ml hot deionized water in a 250-ml PTFE beaker and dissolve residue by agitation. Wash the crucible with hot deionized water and remove it. Add 50 ml hydrochloric acid and transfer the contents into a 250-ml polypropylene volumetric flask. Wash the beaker three times with hot deionized water, transfer the washings to the volumetric flask and make up to volume (Solution A). Prepare the test solution by diluting Solution A with 2% hydrochloric acid. Analyze calcium and silicon in the test solution by ICP-AES technique (Vol. 4). Set instrument parameters as specified by the instrument manufacturer. Use analytical lines for Ca (393.366 nm) and Si (251.611 nm). Read the concentration of Ca and Si in sample solution (as μg/ml) from respective standard curves. Calculate the calcium oxide and silicon dioxide content of the sample on the anhydrous basis using the formula: 1.399 ൈ C ൈ 250 ൈ DF CaO ሺ%ሻ ൌ ൈ 100 W ൈ 10 2.139 × C × 250 × DF SiO2 (%) = 6 × 100 W × 10 where C is concentration of Ca or Si in the test solution, μg/ml W is weight of sample on the ignited basis, g DF is dilution factor (dilution of Solution A to test solution).
Identification
- Solubility (Vol. 4)
- Insoluble in water and ethanol
- pH (Vol. 4)
- 8.4-12.5 (5% slurry)
- Test for calcium
- Passes test See description under TESTS
- Test for silicon
- Passes test See description under TESTS
- Test: Test for calcium and silicon
- Prepare the test solution as shown under method of assay. Analyze calcium and silicon in the test solution by ICP-AES technique (Vol. 4). Set instrument parameters as specified by the instrument manufacturer, use the analytical lines for Ca (393.366 nm) and Si (251.611 nm).
Purity criteria
- Loss on drying (Vol. 4)
- Not more than 10% (105°, 2 h)
- Loss on ignition (Vol. 4)
- 5.0–14.0% on the dried basis (1000°, constant weight)
- Fluoride (Vol. 4)
- Not more than 50 mg/kg Weigh 1 g of the sample to the nearest mg, and proceed as directed in the Fluoride Limit Test (Method II).
- Impurities soluble in 0.5 M hydrochloric acid
- Lead : Not more than 5 mg/kg Arsenic: Not more than 3 mg/kg See description under TESTS
- Test: Impurities soluble in 0.5 M hydrochloric acid
- Extract 20 g of finely ground sample under reflux conditions with 100 ml of 0.5 M hydrochloric acid (spectroscopic grade) for 30 min. Let solution cool, then, filter through a 0.1 μ m membrane filter. Wash the filter twice with hot 0.5 M hydrochloric acid. Combine the filtrate and wash solution in a 200 ml volumetric flask and make up to volume with 0.5 M hydrochloric acid. Determine arsenic using an AAS (Hydride generation) technique; and lead using an AAS (Electrothermal atomization) technique. See “Metallic impurities” in the Combined Compendium of Food Additive Specifications (Volume 4).
Authorised in other additives, enzymes, flavourings and nutrients
These authorisations are not for use in food. They let this substance be used inside another additive, a food enzyme, a flavouring or a nutrient preparation — often as a carrier — and it reaches food only as part of that product. Annex III to Regulation (EC) No 1333/2008.
| Part | May be used in | Maximum level | Citation |
|---|---|---|---|
| Annex III, Part 1: Carriers in food additives | Emulsifiers and colours | quantum satis | Regulation (EC) No 1333/2008, Annex III, Part 1 |
| Annex III, Part 2: Food additives other than carriers in food additives | Dry powdered preparations of emulsifiersNote (1): Except enzymes authorised as food additives. | 50 000 mg/kg in the preparation | Regulation (EC) No 1333/2008, Annex III, Part 2 |
| Annex III, Part 2: Food additives other than carriers in food additives | Dry powdered preparations of polyolsNote (1): Except enzymes authorised as food additives. | 10 000 mg/kg in the preparation | Regulation (EC) No 1333/2008, Annex III, Part 2 |
| Annex III, Part 5, Section A: Food additives added in nutrients except in nutrients intended to be used in foodstuffs listed in Part E, point 01.10, of Annex II and foodstuffs for infants and young children listed in Part E, point 13.1, of Annex II | In dry powdered preparations of all nutrientsListed jointly as "E 551, E 552 Silicon dioxide Calcium silicate" | 50 000 mg/kg in the dry powdered preparation (singly or in combination) | Regulation (EC) No 1333/2008, Annex III, Part 5, Section A |
| Annex III, Part 5, Section A: Food additives added in nutrients except in nutrients intended to be used in foodstuffs listed in Part E, point 01.10, of Annex II and foodstuffs for infants and young children listed in Part E, point 13.1, of Annex II | In potassium chloride preparations used in salt substitutesListed jointly as "E 551, E 552 Silicon dioxide Calcium silicate" | 10 000 mg/kg in the preparation (E 551 only) | Regulation (EC) No 1333/2008, Annex III, Part 5, Section A |
Every name it appears under
27 recorded names. A label may use any of them.
E number
- E552
INS number
- 552
CAS registry number
- 10101-39-0
As it appears in regulation
- Calcium silicate
Other names
- Calcium monosilicate
- Calcium silicate
Systematic names
- Calcium;dioxido(oxo)silane
The EU re-evaluation programme
Every additive authorised in the EU before 20 January 2009 was put back through EFSA by Commission Regulation (EU) No 257/2010, and this one is named in it. What the Regulation required is below; whether the opinion has since been published is not something this site records.
- To be evaluated by 31 December 2018. Named in Annex II, Part II, point 4 as “Calcium silicate”, among the additives given priority within its class.
Hazard reference values
| Type | Value | Population | Assessed by | Opinion |
|---|---|---|---|---|
| ADI | not specified | — | JECFA | 2015 |
Evidence and how bodies read it
What assessing bodies concluded
Each conclusion is paraphrased in the body's own framing, from the published opinion linked beneath it. Where bodies differ, both stand; this site does not adjudicate between them or add a view of its own.
EFSA 2018
The ANS Panel concluded that the safety of calcium silicate (E 552), magnesium silicate and trisilicate (E 553a) and talc (E 553b) as food additives cannot be assessed, citing accumulation of silicon in rat kidney and liver and a lack of reliable longer-term toxicity data. It considered the SCF's group ADI for silicon dioxide and silicates obsolete and recommended revisions to the specifications.
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 552?
- E 552 is Calcium silicate. Calcium silicate is an anticaking agent, used in table salt, baking powder and powdered mixes. It absorbs many times its weight in moisture, which is how it keeps a powder flowing.
- What is Calcium silicate used for in food?
- It is listed as an anticaking agent — the role Canada, Codex and the US assign it. This page shows every function each regulator records, with the citation for each.
- Where is Calcium silicate permitted?
- Of the seven regulators this site reads, Australia and New Zealand, Canada, the EU, Great Britain, Japan, South Korea, the US and the Codex standard 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 silicate vegan?
- Yes. Calcium 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
- ca retrieved 2026-10-17
- eu retrieved 2026-10-18
- gb retrieved 2026-10-18
- jp retrieved 2026-10-18
- kr retrieved 2026-10-18
- ecfr retrieved 2026-10-17
- gsfa retrieved 2026-09-07
- euspecs retrieved 2026-10-18
- jecfaspecs retrieved 2026-09-23
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