Silicon dioxide

Studies in people

• Open question

  Particles in body organs¹

  Silicon dioxide particles were found in liver, spleen, kidney and gut tissue of 15 dead people.

Animal and lab studies only

• Concern

  Gut nutrient absorption⁵

  In lab studies, silicon dioxide tiny particles changed how the gut took in iron, zinc, glucose and fats.

• Concern

  Immune cell reaction⁶

  In lab studies, silicon dioxide particles made immune cells act switched on and pushed T-cells to multiply.

Study type not stated

• No harm found

  Additive in infant formula²

  Experts looked at silicon dioxide in infant formula and found no safety concern at current levels.

• Open question

  Gut immune system³

  Scientists do not yet know whether silicon dioxide particles in food affect the gut's immune cells.

How it’s made and used

• How much gets absorbed⁴

  In rats, the body absorbed more silicon dioxide from tiny particles than from larger ones, and sugar or protein changed how fast.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.

Expert panels that weigh all the research. Shown for context: the signal at the top does not count them. IARC rates whether something can cause cancer at all, not how likely it is at the amounts in food.

• UN and WHO food additive experts (JECFA), 2017

  No daily limit needed (“ADI not specified”, JECFA’s term for very low toxicity).

• WHO cancer agency (IARC), 1996

  For amorphous silica: not enough evidence to say whether it causes cancer in people (Group 3).