New alert on the use of silver nanoparticles in masks

In early February 2023, researchers from the Belgian research institute sciensano have published in the journal Science of the Total Environment, Analyses of a research project initiated in 2020 on the silver particles in the masks.

They call to frame more the application of biocides on the masks and D'intensify research related to potential health and environmental risks, joining the recommendations in this direction already formulated by various organizations including AVICENN. These analyzes were the subject of a report by Sciensano published in 2022 and available here.

The AgMask project

Faced with the growing marketing of masks covered with a virucidal treatment, Sciensano had launched the AgMask project in 2020, to assess the types, efficacy and health risks of silver-based biocides used in masks. 

De first results had already been published in 2021, reporting on the use of titanium dioxide and silver nanoparticles in Avrox masks. 

Secondly, Sciensano analyzed twenty masks for the general public : silver was detected in thirteen masks (in ionic, metallic form and in four masks, in nanoparticle form). By comparing the silver content of the masks to the inhalation exposure limits already established by the US National Institute for Occupational Safety and Health (NIOSH), the researchers distinguished two groups of masks.

•  on the one hand, 7 masks can be considered safe (“safe-by-design”)
• the other 6 masks exceeding exposure limit values and for which it is necessary to carry out a more in-depth risk assessment; one of them was even withdrawn from the market by the Belgian authorities because it contained far too high a silver content.

The risk-benefit balance in question

Why is silver used by mask makers? This substance has antimicrobial properties that limit the transmission of bacteria and can facilitate the preservation of fabrics and limit bad odors, all properties that brands do not hesitate to use as a selling point.

However, exposure to silver ions and silver nanoparticles can have harmful effects: alleged risks ofsevere nervous system effects (neurotoxicity following repeated or prolonged exposure), fertility risks and hazards to the aquatic environment. Money is like that being classified at European level. 

Today, nano-silver is no longer authorized in Europe as a biocide in masks

Nanosilver can no longer be used as a biocidal substance since 2021 for product types 2, 4 and 9 following a decision by the European Commission. However, the researchers point out, the anti-viral activity of silver nanoparticles remains a selling point…

Sciensano recommends better regulation of nanosilver

As indicated by the Sciensano researchers, their results argue in favor of a extensive research on the applications of silver-based biocides in masks and on the applications of nanotechnology in masks in general. Regulations must be commensurate with potential health and environmental risks posed by these biocidal coatings, already widely marketed in the medical environment as well as with the general public – as evidenced in France by the tests carried out on sports textiles by the DGCCRF et on a children's toothbrush by AVICENN.

Concerns already raised by ANSES, AVICENN and twelve European NGOs

This is an observation that was underlined by theANSES in 2020 then AVICENN and twelve other European NGOs in 2021: the regulation of articles treated with nano/biocides lags behind the commercialization of new products and does not guarantee their safety. 

In January 2021, these NGOs published a open letter sent to the European Chemicals Agency (ECHA) requesting clarification of the regulatory framework and more information on anti-covid-19 nano product monitoring. ECHA's response returned the ball to the Member States, responsible for monitoring the proper application of the Biocides Regulation.  

Sciensano's study shows how urgent it is to act; Member States can no longer turn a blind eye and must uphold the precautionary principle emanating not only from associations and health authorities but also from the scientific community.

A limited risk assessment… but not for long?

Sciensano researchers remain cautious about the results, because it is difficult today to measure the release of silver particles from the mask towards the user and to have a precise idea of ​​the level of exposure by inhalation. .

The “Renaame” project, which brings together Sciensano in Belgium, the National Metrology and Testing Laboratory (LNE) and the National Research and Safety Institute (INRS) in France, has just been launched in order to develop a validated test methodology for assessment of the potential release in the aerosol phase of nanomaterials (titanium dioxide, silver, copper, magnesium oxide, etc.) by masks with or without treatment claims. This project was selected by ANSES as part of its call for environmental-health-work research projects and benefits from funding of €200 from the ministries responsible for the environment, agriculture and labour. 

To be continued ...