anti-caking agent INS 551

Silicon Dioxide E551

carrier, filter aid — Primarily mineral or synthetic.

🇪🇺 EU: Approved

🇺🇸 USA: Approved

🇯🇵 Japan: Approved

🇦🇺 AU/NZ: Approved

🇨🇦 Canada: Approved

Scientific Name

Silicon dioxide (SiO2)

CAS: 7631-86-9 (amorphous), 14808-60-7 (crystalline)

Data verified: 2026-04-04

Global Status

European Union approved

United States approved

Japan approved

Canada approved

AU / NZ approved

Also Known As

SilicaAmorphous silicaQuartz (crystalline form, not used in food)Sand (impure crystalline form)

Commonly Found In

TABLE SALT (anti-caking - keeps salt free-flowing) Powdered coffee creamers Spice mixes and dried seasonings Powdered soups and gravies Powdered drink mixes Icing sugar and powdered sugar Dietary supplements (tablets and powders) Dried egg powder Instant coffee

Typical product categories; may vary by brand. Always check the physical label.

Similar Additives

Potassium Ferrocyanide

E538

Calcium Ferrocyanide

Factual Regulatory Reference

This database provides factual regulatory information compiled from official government sources. It does not constitute medical, nutritional, or safety advice. Regulatory status varies by country and is subject to change. Always refer to your local regulatory authority for the most current information.

? Did You Know?

Silicon Dioxide occurs naturally in Quartz (crystalline silica) and Sand. Many people consume it daily without realizing it's also a listed food additive.

Beyond food, Silicon Dioxide is also used in cosmetics, medicine, industrial applications, household products. Its versatility makes it one of the most multi-purpose chemical compounds in everyday life.

Detailed Regulatory Assessment

🇪🇺

European Union (EFSA)

approved Max: quantum satis (10000 mg/kg in many categories) mg/kg

Only amorphous silica permitted. Maximum levels specified for certain food categories.

Official EFSA Link

🇺🇸

United States (FDA)

approved GRAS

Widely used as anti-caking agent. Maximum 2% by weight in food.

🇯🇵

Japan (MHLW)

approved Cat: 指定添加物

Compliant with Japanese food sanitation law.

Acceptable Daily Intake (ADI)

International Standard (JECFA)

not specified (acceptable for use at levels used)

mg/kg body weight per day

European Standard (EFSA)

not specified (no safety concern for amorphous silica at current use levels)

Natural Occurrence

Silicon dioxide is one of the most abundant compounds on Earth, making up most sand and many rocks. Food-grade silica is amorphous (non-crystalline) form, not the crystalline quartz found in nature.

Quartz (crystalline silica)SandDiatomaceous earth (fossil diatoms)Most rocks and minerals

Manufacturing

Method: chemical synthesis or mining

Food-grade amorphous silica is produced by synthetic processes (precipitated silica, fumed silica, silica gel) or by purifying natural diatomaceous earth. The amorphous form is essential - crystalline silica (quartz) is not used in food due to health concerns.

Applications Beyond Food

Cosmetics

Absorbent, abrasive, bulking agent, opacifier in cosmetics and toothpaste.

Medical

Tablet and capsule diluent, glidant, anti-caking agent.

Industrial

Glass manufacturing, electronics, concrete, water filtration, insulation.

Household

Desiccant packets ('do not eat'), cat litter, toothpaste abrasive.

Frequently Asked Questions

What is Silicon Dioxide (E551)?

Silicon Dioxide (E551) is a anti-caking agent used in food products. It is carrier, filter aid and mineral or synthetic. Silicon dioxide is one of the most abundant compounds on Earth, making up most sand and many rocks. Food-grade silica is amorphous (non-crystalline) form, not the crystalline quartz found in nature.

Where is Silicon Dioxide found naturally?

Silicon Dioxide is naturally found in Quartz (crystalline silica), Sand, Diatomaceous earth (fossil diatoms), Most rocks and minerals. Silicon dioxide is one of the most abundant compounds on Earth, making up most sand and many rocks. Food-grade silica is amorphous (non-crystalline) form, not the crystalline quartz found in nature.

What is the ADI for Silicon Dioxide?

The Acceptable Daily Intake (ADI) for Silicon Dioxide is not specified (acceptable for use at levels used) as established by JECFA (Joint FAO/WHO Expert Committee on Food Additives). ADI represents the amount that can be consumed daily over a lifetime without appreciable health risk.

What foods contain Silicon Dioxide?

Silicon Dioxide is used in various food categories including Table salt and salt substitutes, Seasonings and condiments. It is used as a anti-caking agent in these products.

Is Silicon Dioxide the same as Silica?

Yes, Silicon Dioxide is also known as Silica, Amorphous silica, Quartz (crystalline form, not used in food), Sand (impure crystalline form). These are different names for the same substance.