Silicon dioxide (E 551) safety in food, including infant formula
What it found
The authors found that silicon dioxide (E 551) does not raise a safety concern at the reported uses and use levels in all population groups, including infants below 16 weeks of age.
The assessment used animal studies, lab tests, and existing data on a medicine containing the same substance.
What they found
Animal and lab studies
General toxicity in animals
No adverse effects were seen on general health, body weight, appearance, behaviour, blood, or organs in animal studies up to the highest dose tested of 5000 mg per kg body weight per day.
Liver and spleen
The liver and spleen had the highest silicon levels after dosing, but no adverse effects were found on their weight, tissue, or liver enzymes up to 5000 mg per kg body weight per day.
Reproduction and development
No adverse effects were reported on reproduction or development at doses up to or exceeding 1000 mg per kg body weight per day.
Immune system
The authors concluded it is likely that E 551 has no adverse effects on the immune system, but they noted that its ability to cause low-grade gut inflammation and possibly food allergy or coeliac disease needs more study, especially in people.
Damage to genetic material
The authors concluded that E 551 does not raise a concern for damage to genetic material, based on the available studies.
Other findings
Infants below 16 weeks
No human or animal data were available for this age group. The authors compared exposure from infant formula (up to 3 mg per kg body weight per day) to a medicine containing the same substance (simeticone) used in infants at 2.37 mg per kg body weight per day without side effects, and found no safety concern at current exposure levels.
What the authors conclude
“The Panel concluded that E 551 does not raise a safety concern in all population groups at the reported uses and use levels.”
Also in their conclusions
- They concluded that E 551 does not raise a safety concern in all population groups at the reported uses and use levels.
- They also concluded that the use of E 551 in food for infants below 16 weeks of age does not raise a safety concern at the current exposure levels.
- They recommended lowering the maximum limits for lead, mercury and arsenic and introducing a maximum limit for aluminium in the specifications for E 551.
How it was done
The authors did this work to follow up on data gaps and uncertainties from a 2018 safety assessment of silicon dioxide (E 551) and to assess its safety for use in food for infants below 16 weeks of age, which had not been covered before.
They reviewed new data from companies and published studies on the properties and toxicity of silicon dioxide (E 551), including studies in animals and lab tests. They also estimated dietary exposure for all age groups and for infants below 16 weeks of age, and compared it to a reference point from animal studies.
What it can’t tell you
- The available animal studies cannot show what happens in people, especially for infants below 16 weeks of age, because no human or animal data exist for that age group.
- The studies cannot fully show the effects of the smallest particles (nanosize aggregates) because only two short studies with low doses looked at them.
- The authors note uncertainty about the size and clumping of particles in food, which limits the assessment.
Who paid
- Conflicts
- If you wish to access the declaration of interests of any expert contributing to an EFSA scientific assessment, please contact interestmanagement@efsa.europa.eu.
The paper
- Title
- Re-evaluation of silicon dioxide (E 551) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as a food additive for uses in foods for all population groups
- Type
- Scientific opinion of the European Food Safety Authority
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Licence
- CC BY-ND. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- EFSA Panel on Food Additives and Flavourings (FAF), Younes M, Aquilina G, et al (2024). Re-evaluation of silicon dioxide (E 551) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as a food additive for uses in foods for all population groups. EFSA journal. European Food Safety Authority. doi:10.2903/j.efsa.2024.8880Free full textPubMed 39421729DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error