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E551 / Acidity regulators & anti-caking agents

Silicon Dioxide

Selected sources checked · Scope & sources

Safety in brief

Safe

Recorded EatMatrix rating, not a new clinical review. The amount, your sensitivities and country rules still matter.

Watch for
No allergen or sensitivity is recorded for this ingredient here. Check the whole product label; this is not an allergen-free guarantee.
Our advice
Read the whole food label and consider how often you eat the product. A name or E number does not tell you the amount, and an ingredient rating cannot assess the entire food.
What it is

Silicon dioxide, commonly known as silica, is a mineral compound also found naturally in quartz and sand. In food, synthetic amorphous silica is used as an anti-caking agent to keep powdered foods like spices, coffee creamer, and powdered sugar free-flowing. Regulatory bodies (EFSA, FDA) consider it safe for food use; it is poorly absorbed and passes through the digestive system largely unchanged. EFSA has noted uncertainty about nanoparticle content in some silica preparations, prompting an ongoing safety re-evaluation, though no acute risk has been established at typical use levels.

Also appears on labels as: Silicon dioxide, E551, E 551, E-551, Silica, Colloidal silica, Amorphous silica, Synthetic amorphous silica, Precipitated silica, Fumed silica, Silicic anhydride, Silicon(IV) oxide.

Dietary information

Vegan
Yes
Halal
Yes
Gluten-free
Yes
Allergens
None recorded

Recorded ingredient information. Check the product label or certification: sources, other ingredients and cross-contact can vary.

Research & body effects

Health notes from our ingredient record

  • Generally recognized as safe at typical food levels.
  • EFSA has flagged data gaps regarding nanoparticle-sized silica particles and is continuing to review long-term safety.

Other references from our ingredient record

These links come from the original ingredient record. They are separate from the source reviews above and have not all been checked for the exact ingredient, amount consumed or claim. Dates are shown newest first.

  1. Re‐evaluation of silicon dioxide (E 551) as a food additive — EFSA Panel on Food Additives, EFSA Journal (2018). Official EFSA scientific opinion (bibliographic reference, imported 2026-10-13). It covers the additive as a group assessment and is not an individual human study; read the opinion for its findings.
Country rules

Country checks for E551

Permission depends on the market, type of food, amount and conditions. A scientific opinion or an E-number alone does not establish a legal use. These checks are separate from the stored EatMatrix rating.

Compare all eight markets and their sources
MarketWhat is checked
European Union

Regulation (EC) 1333/2008, Annex II Part B, version , contains the exact code E551: Silicon dioxide.

Listing alone does not allow every food use. Part E food categories, limits, specifications and applicable later acts still need a product-specific check. Source read: .

Great Britain

The FSA register record for E551 (Silicon dioxide) lists “Authorised” in England, Scotland and Wales.

Register updated: 01 April 2025; record checked: . Food-specific conditions and specifications still need a separate legal check.

United States

Selected US conditions for Silicon dioxide

Official federal text current through ; read .

Food uses, limits and exceptions

Named preparation and use conditions

Anticaking use is limited to foods where the effect has been demonstrated, at no more than needed and no more than 2% by food weight. Beer-stabilising use requires removal by filtration before final processing. A separate narrowly defined adsorbent use applies in tableted special-dietary foods. Particle characteristics and intended use are part of the conditions.

21 CFR 172.480

EatMatrix’s reading: a legal use condition answers where and how an ingredient may be used. It is not a test of your product, a personal safe intake or a claim that the ingredient benefits your body. Match the named substance, food and amount. Other federal provisions, food standards, state rules and later changes may also apply; this is a selected source review, not a complete product-compliance decision.

Northern Ireland

Review pending. Check the applicable EU rules and territory arrangements; the GB register alone does not establish this status. FSA guidance is a starting source, not a verified permission for this entry.

Canada

Named food-use records located. Health Canada lists the preparations below for specified foods and purposes. This is conditional permission for those uses, not approval of every product or a personal safety verdict.

Only the named records and conditions below were located. Exact composition and specifications still need matching.

Source tables captured . List publication dates are shown separately. Good Manufacturing Practice (GMP) is a condition of use, not an unlimited amount or a recommended intake.

Food and Drug Regulations B.16.003 requires the listed source, purpose, amount and other conditions to match. The official consolidation read was current to 21 September 2026; product specifications and applicable later changes still need checking.

Read 10 listed food-use conditions

Silicon Dioxide

Health Canada: List of Permitted Anticaking Agents. List published ; item S.1.

  • Food: (a) Cayenne pepper; Chili pepper; Chili powder; Paprika; Red pepper

    Purpose: (a) Anticaking agent

    Limit and conditions: (a) 2.0%

  • Food: (b) Celery pepper; Celery salt

    Purpose: (b) Anticaking agent

    Limit and conditions: (b) 5,000 ppm

  • Food: (c) Foods sold in tablet form

    Purpose: (c) Anticaking agent

    Limit and conditions: (c) Good Manufacturing Practice

  • Food: (d) Garlic salt; Onion salt

    Purpose: (d) Anticaking agent

    Limit and conditions: (d) If used singly, the amount not to exceed 1.0%. If used in any combination with other anticaking agents, the total combined amount not to exceed 2.0%, provided that the amount of silicon dioxide does not exceed 1.0%.

  • Food: (e) Icing sugar

    Purpose: (e) Anticaking agent

    Limit and conditions: (e) Not to be used with starch in accordance with paragraph 15.1.5(b) of Volume 15 of the Food Compositional Standards Document. If used singly, the amount not to exceed 1.5%. If used in any combination with other anticaking agents, the total combined amount not to exceed 1.5%.

  • Food: (f) Salt

    Purpose: (f) Anticaking agent

    Limit and conditions: (f) If used singly, the amount not to exceed 1.0%, or 2.0% in the case of fine grained salt. If used in any combination with other anticaking agents, the total combined amount not to exceed 1.0%, or 2.0% in the case of fine grained salt. This total combined amount does not include any of propylene glycol, potassium ferrocyanide or sodium ferrocyanide that may be added up to their respective maximum levels of use set out in this list.

  • Food: (g) Unstandardized dry mixes

    Purpose: (g) Anticaking agent

    Limit and conditions: (g) Good Manufacturing Practice

Silicon Dioxide

Health Canada: List of Permitted Food Additives with Other Purposes of Use. List published ; item S.2.

  • Food: (a) Colouring agent formulations

    Purpose: (a) Colour stabilizer

    Limit and conditions: (a) Good Manufacturing Practice

    Source modification reference: NOM/ADM-0041 (see the official list).

  • Food: (b) Edible vegetable oil-based cookware coating emulsions

    Purpose: (b) Suspending agent

    Limit and conditions: (b) 2.0%

  • Food: (c) Modified sugar

    Purpose: (c) To increase dissolution rate

    Limit and conditions: (c) 2,000 ppm

    Source modification reference: MFAA-2601 (see the official list).

EatMatrix reading: match the exact preparation and food first. A manufacturing limit is not an acceptable daily intake (ADI). A label without the amount cannot establish exposure, and an unlisted name here does not establish a ban.

Australia

Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry.

New Zealand

Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry.

Japan

Review pending. The relevant list, identity and use standards need an additive-specific check. CAA food-additive lists is a starting source, not a verified permission for this entry.

Sources & review status

Check what each source covers: an authority’s conclusion, a research finding and a country’s legal permission answer different questions.

What this guide covers

Official assessment sources
Commission-listed EFSA references for E551. Bibliographic identity checked; latest findings and current use rules need separate review.
Original ingredient record
1 research link; newest recorded date: . Sources added separately to this guide are not included in this count.

This guide brings together our ingredient record and the dated sources shown here. Missing information describes a gap in this guide; it does not mean an ingredient is untested, safe or harmful. This is not a complete review of every study, preparation or current country rule. The amount in a product and how it is used still matter.

How to read the ratings, research and country checks
Agency labels recorded by EatMatrix

These are imported database classifications, not verified current statements from each authority. Use the dated official sources below for their actual scope and conclusions.

AuthorityDatabase label
FDASafe
WHONo rating recorded
EFSASafe
FSANZNo rating recorded
JapanNo rating recorded
UK FSANo rating recorded
Health CanadaNo rating recorded

Official assessment sources for E551

The European Commission’s re-evaluation table lists official EFSA documents for this additive. Their identifiers and subjects were checked against publisher bibliographic records. A missing research link in the EatMatrix database does not mean the additive has never been assessed.

Name in the Commission table: Silicon dioxide.

These are assessment references, including historical or group assessments. They do not establish the latest scientific conclusion, a human health benefit or risk, or current permission to use the additive in a particular food. Later assessments, corrections and food-use conditions need separate review. The recorded EatMatrix rating above is unchanged.

European Commission re-evaluation table, status as of . EatMatrix checked this bibliography on .

Database updated: . What does an E number mean on a food label?

Common questions

Frequently asked questions

What is EatMatrix's recorded rating for E551?

The recorded EatMatrix rating for E551 (Silicon Dioxide) is “Safe”. It is calculated from labels stored in our ingredient database. These labels are not verified current regulator decisions or country permissions. A database update date is not a scientific review date.

Is E551 vegan, halal or gluten-free?

According to our ingredient data for Silicon Dioxide — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.

What is E551 and why is it used?

Silicon dioxide, commonly known as silica, is a mineral compound also found naturally in quartz and sand. In food, synthetic amorphous silica is used as an anti-caking agent to keep powdered foods like spices, coffee creamer, and powdered sugar free-flowing. Regulatory bodies (EFSA, FDA) consider it safe for food use; it is poorly absorbed and passes through the digestive system largely unchanged. EFSA has noted uncertainty about nanoparticle content in some silica preparations, prompting an ongoing safety re-evaluation, though no acute risk has been established at typical use levels.

Does E551 contain allergens?

No known allergens are recorded for Silicon Dioxide.

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This page shows information and classifications recorded in our ingredient database. Current scientific and market-specific verification remains pending as described above. It is general information, not medical advice.