Key points about food-grade silica - all in one article!

Document 1: What is food-grade silicon dioxide (SiO₂)?
Food-grade silicon dioxide (SiO₂) is an amorphous silicon dioxide purified and processed to meet the safety standards of food additives. It is mainly produced by gas phase method or precipitation method, and is a white powder with the characteristics of tasteless, odorless and chemical inertness.
As a legal food additive (EU code E551, China CNS number 02.004), its core functions are anti-caking, flow aid, stabilization, and adsorption. It is widely used in foods such as milk powder, condiments, and beverages, and must meet the purity and heavy metal limit requirements set by international/domestic authoritative institutions including the FDA, EFSA, and GB 2760.
Document 2: Is food-grade silica safe for human consumption?
Yes, food-grade silica that meets the standards is safe for human consumption.
International regulatory bodies such as the U.S. FDA (classified as GRAS safe substance) and Europe's EFSA have approved its use within specified doses, confirming no health risks. Three key factors ensure safety: First, its chemical inertness prevents reactions with human tissues or food components. Second, humans cannot absorb amorphous silica dioxide, which is completely excreted through feces without accumulation. Third, production processes strictly control heavy metal content (e.g., lead, arsenic) to below 0.01%, effectively preventing harmful impurities from entering the body.
Document 3: What are the side effects of eating silicon dioxide in food? (What are the side effects of eating food with silica?
Food-grade silica has no known side effects when eaten in the prescribed dose of food additives.
Long-term excessive intake of non-food-grade silica (such as industrial-grade products containing impurities or crystalline silica) may irritate respiratory or digestive tracts through particle deposition. However, this situation differs from the compliant addition of silica in food products. Cases of allergic reactions in individuals with sensitive constitutions are extremely rare, and no authoritative research has confirmed that safe consumption would cause adverse effects.
Document 4: Is silica approved by FDA and EFSA for food use?
Yes, silica has been officially approved for use in food by the FDA (US Food and Drug Administration) and EFSA (European Food Safety Authority).
•The FDA has classified it as a GRAS (generally considered safe) substance, allowing it to be used in food as needed (no specific limits, based on the principle of "reasonable necessity");
•Through the evaluation (EFSA Journal 2018; 16(10)), EFSA confirmed that it is safe as a food additive (code E551) under specified application scenarios, with no daily allowable intake (ADI) limit, and clarified the technical requirements such as production process and purity.
Document 5: What is E551 food additive? (E551 is the EU code for silicon dioxide) (What is the food additive E551? (E551 is the EU code for silicon dioxide))
E551 is the official code for silica in the EU food additive numbering system, covering food-grade fumed silica, precipitated silica and silica gel (different forms of amorphous silica).
As a multi-functional food additive approved by the European Union, E551 is mainly used to prevent powder foods (such as milk powder and spices) from clumping, improve powder flowability, stabilize beverage system, and adsorb volatile flavor substances. It must meet the purity standards of EU Regulation (EC) No 1333/2008 (e.g., SiO₂ content ≥99%, heavy metal limit ≤0.002%).
Document 6: Does food-grade silica accumulate in the human body? (Does food-grade silica accumulate in the human body?)
No, food-grade silica doesn't accumulate in the body.
The key reason lies in the amorphous structure of food-grade silica, which typically has particle diameters at the micron level. The human digestive system cannot break down or absorb this inert substance—— It is neither soluble in water nor stomach acid, and does not chemically react with digestive fluids. Consequently, it is completely excreted unchanged through feces, posing no risk of tissue deposition or accumulation. This conclusion has been confirmed by long-term safety evaluations conducted by institutions including the FDA and EFSA.
Document 7: Is silica in food natural or synthetic? (Is silica in food natural or synthetic?
Silica in food is mainly synthesized, with a small amount from natural extracts (but purified).
•Synthetic silica: produced by gas phase method (silicon tetracloride hydrolysis) or precipitation method (sodium silicate and acid reaction), with high purity and controllable performance, is the mainstream source in food industry (e.g., anti-caking agent, stabilizer);
•Natural silica: extracted from natural minerals such as quartz sand and diatomite, which need to be purified to remove impurities (such as heavy metals and crystalline silica), and only used in a few specific scenarios (such as filter additives), but its safety and functionality are not fundamentally different from synthetic products.
Document 8: Can people with allergies eat food containing silicon dioxide? (Can people with allergies eat food containing silicon dioxide?)
Usually yes, food grade silica rarely causes allergic reactions.
Silica itself is chemically inert and does not belong to common allergens (such as milk, nuts, gluten). Currently, there are no authoritative medical reports worldwide that confirm that it causes allergies.
If people with allergic constitution feel uncomfortable after eating food containing silica, it is more likely to be related to other ingredients in the food (such as spices and preservatives) rather than silica itself. If in doubt, check the food ingredient list to exclude other allergens or consult a doctor.
Document 9: Are nanoparticles in food-grade silica safe? (Is it safe to have nanoparticles in food-grade silica?)
At present, the international authority believes that a small amount of nanoparticles (particle size <100nm) in food grade silica is safe to use within the prescribed dose.
Research by the U.S. Food and Drug Administration (FDA), European Food Safety Authority (EFSA), and other agencies confirms that food-grade silica nanoparticles, despite their small particle size, maintain an amorphous structure. These particles aggregate with others to form micrometer-scale aggregates that cannot be absorbed by the human body and are ultimately excreted through feces. Moreover, production processes strictly control nanoparticle content to prevent excessive accumulation. As of 2024, there is no evidence indicating that nanoparticles in compliant food-grade silica pose health risks to humans.
Document 10: Does silica affect the nutritional value of food?
No, silica does not affect the nutritional value of food.
The core reason lies in the extreme chemical inertness of silica dioxide. It does not react with nutrients like proteins, vitamins, and minerals in food, nor does it disrupt nutritional structures. Moreover, since it isn't absorbed by the human body, it functions solely as a "functional additive" (such as anti-caking and stabilizing effects). After use, it is excreted through feces without interfering with the digestion and absorption of food nutrients.........