Nanomaterials: a challenge for the future of the chemical industry?
jeudi 22 septembre 2022
Used more and more frequently in everyday products such as cosmetics, medicines, telecommunications tools, etc., nanomaterials promise unprecedented advances in many fields. However, due to their size, on the scale of a billionth of a meter, the size of a virus, their presence raises concerns about the risks they may represent, both for human health and for the environment.
Indeed, a substance in the nanoparticle state may present a different hazard profile from that presented by the same substance in its non-nanoparticle form (ability to cross biological barriers, persistence in the environment, etc.).
To face this new challenge, the regulations had to adapt. As early as 2011, a recommendation (1*) from the European Commission defined a nanomaterial as being a natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 % or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm-100 nm, including by way of derogation fullerenes, graphene flakes and single-walled carbon nanotubes having one or more external dimensions less than 1 nm.
A new recommendation 2022/C 229/01 relating to the definition of nanomaterials has just been published: awaited since 2015, it updates recommendation 2011/696/EU in order to clarify certain terms, to better redefine the scope of application of the definition of nanomaterials and to harmonize the definition with a view to its subsequent inclusion in all European cross-cutting or sectoral regulations. Thus, the term "nanomaterial" now means a natural, incidental or manufactured material consisting of solid particles that are present, either on their own or as identifiable constituent particles in aggregates or agglomerates, and where 50 % or more of these particles in the number-based size distribution fulfil at least one of the following conditions: ∎ One or more external dimensions of the particle are in the size range 1 nm to 100 nm; ∎ The particle has an elongated shape, such as a rod, fibre or tube, where two external dimensions are smaller than 1 nm and the other dimension is larger than 100 nm; ∎ The particle has a plate-like shape, where one external dimension is smaller than 1 nm and the other dimensions are larger than 100 nm.
In order to determine the numerical size distribution of the particles, it is not necessary to consider particles having at least two orthogonal external dimensions larger than 100 μm. A material having a specific surface area by volume of less than 6 m 2 /cm 3 is however not considered to be a nanomaterial.
It is understood by: ∎ “Particle” a minute piece of matter with defined physical boundaries; single molecules are not considered ‘particles’; ∎ “Aggregate” a particle comprising of strongly bound or fused particles; ∎ “Agglomerate a collection of weakly bound particles or aggregates where the resulting external surface area is similar to the sum of the surface areas of the individual components.
The definition of the first recommendation adopted in 2011 had been integrated into some regulations such as Regulation (EC) 1907/2006 (REACH), Regulation (EU) 528/2012 on biocidal products, at European level, and also in the French decree concerning the annual obligation to declare substances with nanoparticle status via the R-nano register (which uses an equivalent definition). It is expected that these sectoral or cross-functional regulations will update their definition to replace it with the new 2022 recommendation.
Concerning the cosmetics regulation, which, from the start, adopted a definition significantly different from the 2011 recommendation, an update of the definition of nano substances is under discussion as part of the revision of the cosmetics regulation.
In addition, through Regulation (EU) 2018/1881 (2*) amending Annexes I, III, VI, VII, VIII, IX, X, XI, and XII of the REACH Regulation, for the purpose of covering nanoforms of substances, companies who manufacture, import or use such substances in the European Economic Area (EEA) now have new constraints concerning: ∎ Characterization of the nanoforms or groups of nanoforms covered by the registration (annex VI) ∎ Chemical safety assessment (annex I) ∎ Information requirements for registration (Annex III and VII-XI) ∎ Downstream User Obligations (Annex XII).
The regulation explicitly states that the nanoforms of a substance must be covered by the registration dossier of the non-nano form, and that the registrant must provide a justification explaining why the information provided in the joint submission is adequate to assess the nanoforms.
These new requirements apply to all registrations, new and existing, covering nanoforms.
Annex VI defines the term "group of similar nanoforms " as a group of characterized nanoforms, for which it remains possible to conclude, from the clearly defined limits for the parameters for each nanoform of the group, that the evaluation of the hazards, exposure assessment and risk assessment of these nanoforms can be carried out jointly. A justification must be provided, demonstrating that a variation within these limits does not affect the hazard assessment, nor the exposure assessment, nor the risk assessment of the similar nanoforms belonging to of the group.
A nanoform can only belong to one group of similar nanoforms.
In order to help manufacturers complying with their obligations, ECHA has published several guides, including the guide "Appendix on nanoforms applicable to the Guidance on the registration and identification of substances" (3*), published in 2019.
Despite this, the overall perception of nanoparticles by public opinion remains today largely that of a field still under exploration and poorly known, promising but potentially risky. With this in mind, and in order to increase the amount of information available, the content of the safety data sheets has also been reviewed. Regulation (EU) 2020/878 thus amends Annex II of Regulation (EC) 1907/2006 and provides for the insertion in the SDS of specific requirements for nanoforms of substances required by Regulation (EU) 2018/1881.
Thus, the SDS must now (or by December 31, 2022 at the latest) mention in each relevant section whether it concerns nanoforms and, if so, specify which ones, and link the relevant safety information to each of these nanoforms. For this purpose, the word “nanoform” should be used.
Furthermore, beyond these European requirements, companies may also have to comply with national requirements. This is the case in France, where manufacturers, importers and distributors of more than 100 g of substances in the nanoparticle state (nanoparticles, nanomaterials or nanotechnologies) must declare the quantities produced, imported or distributed. This annual declaration must be made to the National Agency for Food, Environmental and Occupational Health and Safety (ANSES) before 1 May each year.