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VeilleNanos - Silica nanoparticles

Silica nanoparticles

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Info sheet

By the AVICENN team – Last updated July 2021

Silica nanoparticles

Multiple application sectors

Silica is used by industry in a wide variety of applications. Synthetic amorphous silicas (SAS) are used:

  • in food, as a food additive (E551) or “processing aid”:
    • anti-caking agent in powdered foodstuffs (sugar, salt, flour, cocoa, and many dehydrated products such as soups, instant noodles, coffee, etc.)
    • or viscosity modifier in sauces, soups, dressings, etc.
    • we would absorb on average about 124 mg per day
    • authorized, including in nano form for precisely defined uses (powdered foodstuffs, sugar, salt, seasoning, rice…) in 2009
    • its safety is questionable.
  • as a moisture absorber in many products (including baby diapers and sanitary pads)1Two reports from Anses show this (without specifying the potential associated risks):
    Safety of baby diapers – Revised opinion of Anses, Collective expertise report, Anses, January 2019
    Safety of intimate protection products, Anses, December 2019: the study of the national registry of substances in the nanoparticulate state (r-nano) confirmed that “Silica in the nanoparticulate state is used for its “superabsorbent” properties. It is notably sold to actors involved in the manufacture of diapers and sanitary pads.”)
  • as reinforcing or thickening agents in various systems (elastomers, resins, paints, inks)
  • in beer and wine as clarifying agents
  • as texturizing / fluidizing agents for cosmetic (lipsticks, shampoos, creams), pharmaceutical or toothpaste products
  • for non-stick coating2Cf. e.g. “Nanomaterials – Silica coating more slippery than Teflon”, Die Welt, March 2010 (like Teflon).

Presence of silica nanoparticles in France

According to the Ministry of Ecological Transition and Solidarity3Cf. bilan R-nano 2019, Ministry of Ecological Transition and Solidarity, June 2020, between 10,000 and 100,000 tons of silicon dioxide (SiO2) nanos were officially imported or manufactured in France in 2018. This range is not very precise and should be considered as an indication. Indeed, the quantities registered in the French R-nano register are below the quantities actually present on the French market, as many nanomaterials escape declaration.

Since the implementation of the declaration of “substances in nanoparticulate form” in 2013, it has been confirmed that different nanoforms of silica are imported or produced in France. Several forms of substances in the nanoparticulate state have been declared, under different names: “silica gel”, “silicon dioxide”, “synthetic amorphous silica”, “salicylic acid – magnesium salt”, “silane”, “silicon dioxide”, “silicate”, “silane”, “dichlorodimethyl-“, “products of silica reaction”).

Almost all (if not all) of the primary silica particles used are nanomaterials:

  • SAS used in cosmetics. In July 2019, the European Scientific Committee on Consumer Safety (SCCS) published its final opinion on the solubility of synthetic amorphous silica (SAS)5Opinion on solubility of Synthetic Amorphous Silica (SAS), Scientific Committee on Consumer Safety (SCCS), June 20-21, 2019 (Corrigendum of December 6, 2019) according to which hydrophilic and hydrophobic SAS are to be considered as insoluble or very slightly soluble; under the Cosmetics Regulations 2009, these two SAS are therefore to be considered as nanomaterials and should be labeled with the word [nano].

Vigilance is required because there are significant risks associated with silica nanoparticles.

Any questions or comments? This information sheet compiled by AVICENN is intended to be completed and updated. Please feel free to contribute.

Upcoming Nano Agenda

Managing the risks associated with nanomaterials (CEA, Grenoble)
  • Awareness-raising aimed at personnel in contact with nanomaterials during research, formulation, production, maintenance, cleaning, upkeep, etc., as well as safety coordinators or engineers, facility managers, heads of laboratories where nanoparticles are handled.
  • Organizers: INSTN Grenoble (CEA)
  • On the agenda: potential impact on health; metrology and protection; control of potential risks associated with nanomaterials; consideration of societal aspects.
  • Website:
Nanomaterials and Health (ANSES, Maisons-Alfort)
Dialogue Committee
Nanoparticles NPC-24 (ETH, Zurich)
  • 27th ETH Nanoparticles Conference
  • Organizer: ETH Zurich
  • From June 10 to June 14, 2024
  • Website:

File initially put on line in June 2016

Notes and references

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