Silver nanoparticles

Silver (nano)particles

By the AVICENN team – Last added November 2021

What quantities on the market?

Hundreds of tons of silver nanoparticles are produced every year in the world¹Some estimates of nanosilver production:
– In 2013, a projection was made for global nanosilver production of between 450 and 542 tonnes for 2014 (The global nanotechnology and nanomaterials industry – Technology Report No. 68Future Markets, Inc. 2013)
– In 2011, the production of nanosilver was estimated at 20 tons in the United States alone(Estimating production data for five engineered nanomaterials as a basis for exposure assessment, Hendren CH et al, Environ Sci Technol, 45:2562-2569, 2011)
– In 2008, the world production of nanosilver was estimated at 500 tons per year (cf. Mueller NC and Nowack B, Exposure modeling of engineered nanoparticles in the environment, Environmental Science & Technology, 42(12): 4447-4453, June 2008.

From 2013 to 2017, less than 10 kg of nano silver was reported each year as having been produced and/or imported in France in the context of the mandatory reporting ; in 2018, for the first time, the volume of nanosilver reported moved into the upper range, comprised between 10 and 100 kg²Cf.The R-Nano register – The annual declaration of “substances in the nanoparticulate state” in France, mandatory since 2013, veillenanos.fr.

However, there is much more nanosilver on French soil: this declared “nano-quantity” illustrates the difficulties to apprehend the real quantities of nanomaterials present on French soil via the r-nano register and the annual declaration, victim of the “sieve effect”.

What properties?

Silver nanoparticles are mainly used as antibacterial or antifungal in the medical and pharmaceutical sector, in packaging (cardboard, plastic) and plastic films, in cosmetics (deodorants, soaps,), in small care equipment (hairbrushes, electric razors, toothbrushes, hair dryers, curling irons, etc.), in textiles (medical staff gowns, fabrics used in operating theatres), on computer and telephone keyboards…

Which products?

Several inventories of products containing nano-silver are available online: they list between 200 and 500 products, but are probably far from being exhaustive, given the low compliance with the labeling obligation.

The few kilos of nano-silver (less than 10) declared to the R-nano register in 2017 were classified in the following categoriesCf³.The R-Nano register – The annual declaration of “substances in the nanoparticulate state” in France, mandatory since 2013, veillenanos.fr :

• vehicles
• machines, mechanical devices, electrical/electronic items
• laboratory chemicals
• metals and alloys
• biocidal products (e.g. disinfectants, insecticides)
• use as a laboratory reagent
• production of metal powders (wet process)
• formulation [mélange] of preparations and/or repackaging (except alloys)
• general manufacturing, p. e.g. machines, equipment, vehicles,
• other transport equipment
• scientific research and development
• manufacture of fine chemicals

Silver nanoparticles are present in the food additive E174, a silver colorant used in foods (mainly pastry decorations).

Non-approval as a biocide of silver “as a nanomaterial

In August 2021, the decision of non-approval as a biocide of silver “as a nanomaterial” was published in the Official Journal of the European Union (OJEU) for product types 2, 4 and 9.

From a legal point of view, this decision was taken because of the absence of an application from an industrialist to obtain an authorization to use nano-silver for biocidal purposes⁹Indeed, manufacturers sometimes do not file (or withdraw or do not renew) an application for a biocide that does not meet the stricter requirements of the new Biocidal Regulation (or for which they feel the cost will be too high to meet them). – and not because of the (proven) risks of nano silver for health and/or the environment.

What are the risks?

The nano-silver is in the process of being classified at the European level.

Depending on the use, the “benefit-risk” balance will be different. While it may be positive for strictly circumscribed medical applications (severe burns for example), it is negative in domestic refrigeratorsSee¹⁰for example L’analyse coût-bénéfice de l’usage des nanoparticules dans les réfrigérateurs, ICSI, Les Cahiers de la sécurité industrielle, February 2011.