Substances in database
Example sheet
Database access
Last subscription

Re-evaluation of silicon dioxide (E 551) as a food additive


Published on: Wed, 17 Jan 2018 00:00:00 +0100


The EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) provides a scientific opinion re-evaluating the safety of silicon dioxide (E 551) when used as a food additive. The forms of synthetic amorphous silica (SAS) used as E 551 include fumed silica and hydrated silica (precipitated silica, silica gel and hydrous silica). The Scientific Committee on Food (SCF) established a group acceptable daily intake (ADI) ‘not specified’ for silicon dioxide and silicates. SAS materials used in the available biological and toxicological studies were different in their physicochemical properties; their characteristics were not always described in sufficient detail. Silicon dioxide appears to be poorly absorbed. However, silicon-containing material (in some cases presumed to be silicon dioxide) was found in some tissues. Despite the limitations in the subchronic, reproductive and developmental toxicological studies, including studies with nano silicon dioxide, there was no indication of adverse effects. E 551 does not raise a concern with respect to genotoxicity. In the absence of a long-term study with nano silicon dioxide, the Panel could not extrapolate the results from the available chronic study with a material, which does not cover the full-size range of the nanoparticles that could be present in the food additive E 551, to a material complying with the current specifications for E 551. These specifications do not exclude the presence of nanoparticles. The highest exposure estimates were at least one order of magnitude lower than the no observed adverse effect levels (NOAELs) identified (the highest doses tested). The Panel concluded that the EU specifications are insufficient to adequately characterise the food additive E 551. Clear characterisation of particle size distribution is required. Based on the available database, there was no indication for toxicity of E 551 at the reported uses and use levels. Because of the limitations in the available database, the Panel was unable to confirm the current ADI ‘not specified’. The Panel recommended some modifications of the EU specifications for E 551.

© European Food Safety Authority, 2015

Re-evaluation of silicon dioxide (E 551) as a food additive

Last Tweets

06/06/2016 - 11:11
Nuovo componente inserito: Simmondsia Chinensis (Jojoba) Seed Oil
29/05/2016 - 10:04
Nuovo componente inserito: Linum Usitatissimum seed oil Error
27/05/2016 - 16:38
Nuovo componente inserito: Soybean oil


Project coordinator

Content revision

Toxicological datasheet creation

Website Administration

Subscriptions & Contacts

To get more info about the NOAEL project, go to FAQ section or contact Roberto Narducci at this address: or
For info about subscription costs click the following link or contact Federica Cambiganu:
PIN s.c.r.l. - Piazza Giovanni Ciardi 25, 59100 - Prato