Silicon Dioxide (E551) — What You Need to Know
What Is Silicon Dioxide?
Silicon dioxide (silica) is a natural mineral compound and the most abundant mineral in the Earth's crust. As a food additive, it is used in powdered and granulated foods to prevent clumping by absorbing moisture. It is chemically inert and passes through the body largely unabsorbed. However, the food-grade form is an amorphous (non-crystalline) silica, distinct from crystalline silica which is a known lung hazard when inhaled as dust in occupational settings.
What Is It Used For?
Used in powdered foods, spice mixes, instant soups, table salt, powdered milk, and food supplements to prevent clumping and improve flowability. Also used as a carrier for flavors and other additives.
Safety Assessment
Food-grade amorphous silica is considered safe by EFSA and FDA. Important distinction: crystalline silica (found in sand and rocks) is a known carcinogen when inhaled as dust in occupational settings (quarry workers, miners). Food-grade amorphous silicon dioxide poses no such risk. EFSA confirmed its safety in 2018 and found no evidence of systemic toxicity at food additive levels.
Based on current evidence, Silicon Dioxide is rated Generally Safe with a score of 8/10. This is equal to the average for anti-caking agents (8/10). Last reviewed by regulators: 2018.
Commonly Found In
Always check the label for E551 or 'Silicon Dioxide'
▶Chemical Information
Frequently Asked Questions about Silicon Dioxide
Quick Facts
- E-Number
- E551
- INS Number
- 551
- Category
- Anti-caking Agents
- Origin
- Synthetic
- FDA Status
- GRAS
- EFSA Status
- Authorized
- ADI
- No limit
- Last Review
- 2018
Quick Links
Related Additives
Other anti-caking agents in the same family