Revision of the definition of “nanomaterial” by the European Commission

Revision of the definition of the term “nanomaterial” by the European Commission (2014-2022)

By the AVICENN team – Last modification October 2023

The result of the revision of the recommendation for the definition of the term “nanomaterial” was published in June 2022; it marks the end of a long suspense (the revision was awaited since 2014…) and the beginning of a new adventure: the clarifications announced are not necessarily there and there is a good chance that quarrels on the qualification (or not) of certain substances as “nanomaterial” will continue…

The “revised” definition recommendation was published in June 2022

On June 10, 2022, the Commission published its revised recommendation for the definition of “nanomaterial,” which replaces its previous 2011 recommendation. It reads as follows:

“Nanomaterial” means a natural, incidentally 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 condition:

(a) one or more external dimensions of the particle* are in the size range 1 nm to 100 nm

(b) the particle* has an elongated shape, such as a rod, fiber or tube, where two external dimensions are smaller than 1 nm and the other dimension is larger than 100 nm

(c) 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 the determination of the particle number-based size distribution, particles with at least two orthogonal external dimensions larger than 100 μm need not be considered.

However, a material with a specific surface area by volume of less than 6 m^2/cm³ shall not be considered a nanomaterial.

* “particle” means a minute piece of matter with well-defined physical contours; single molecules are not considered “particles

** “aggregate”: means a particle comprising strongly bound or fused particles

*** “agglomerate”: means 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.

An 8 year overdue, slow and tedious project

As a reminder, this review should have taken place in 2014… In 2011, the European Commission published a first recommendation for a definition that caused a lot of ink to flow. It was foreseen from the outset that this definition would, if necessary, evolve by 2014. In the end, after years of procrastination and postponements, this new definition was published mid-2022, eight years after the planned deadline.

Questions and controversies

As a reminder, the previous 2011 definition recommendation was challenged:

• both by the industrialists who found it too wide
• and by NGOs who, on the contrary, considered it too restrictive as leaving out many nanometric materials.

The new 2022 recommendation is also a source of criticism (some are common to the 2011 definition, others are specific to the new 2022 version). The clarifications announced are not necessarily forthcoming⁴despite the details provided by the Commission staff working document (SWD(2022) 150), and it is likely that disputes will continue to arise over the qualification (or not) of certain substances as “nanomaterials. This is evidenced in particular by the reaction of the NGO CIEL published on June 14, 2022 and the Chemical Watch article relaying the dissatisfaction of CIEL and AVICENN on June 15, 2022. The reservations expressed by the ANSES on the preliminary draft submitted for consultation in 2021 (see below) had not been taken into account by the Commission either⁵Cf. Scientific and technical support note on “the development of a proposal for an updated definition of the term “nanomaterials” based on Recommendation 2011/696/EUAnses, January 14, 2022; Opinion and report on the request for scientific and technical support in drafting a proposal for an updated definition of the term “nanomaterial” based on European Commission Recommendation 2011/696/EU on the definition of nanomaterial, Anses, May 2023. Georges Favre, from the Laboratoire national de métrologie et d’essais (LNE), is less critical of this new definition ⁶Cf. La Commission publie sa nouvelle définition des nanomatériaux, Actu Environnement, 21 juillet 2022.

On May 17, 2023, Anses published an opinion on the new definition following a referral from the agency in 2018. Its conclusions are clear: the new definition of nanomaterials is detrimental to the prevention of health and environmental risks and public authorities must adopt a more inclusive definition.

What about above 100 nm?

Concerning the 1-100nm range (identical to 2011), there is no scientific justification to establish an upper and/or lower size limit to define all nanomaterials⁷See in particular:
– Nanomaterials: for a more protective European definition, Anses, 23 July 2021
– Contribution of AVICENN to the European consultation on the definition of the term “nanomaterial”, AVICENN, June 30th 2021
– Scientific Basis for the Definition of the Term “nanomaterial”, SCENIHR, European Commission, 2010. Results of toxicological studies show toxic effects specifically at the submicron scale above 100 nm, and specifically up to 600 nm scale. The American Food & Drug Administration (FDA) has chosen to define a nanomaterial as a material with at least one dimension smaller than 1000 nm⁸Cf. Reporting Format for Nanotechnology-Related Information in CMC Review, Office of Pharmaceutical Science (FDA), June 2010.
A team of Chinese and American researchers had published a paper on this topic in February 2014⁹Bai Y et al, 100 Nanometers: A Potentially Inappropriate Threshold for Environmental and Ecological Effects of Nanoparticles, About. Sci. Technol., 48 (6) : 3098-3099, 2014.

What about internally structured nano materials?

In contrast to the ISO definition, the 2022 European definition recommendation, like the 2011 definition, excludes internally structured nano-materials¹⁰The International Organization for Standardization (ISO) defines a nanomaterial as “a material with any external dimension at the nanoscale or internal or surface structure at the nanoscale” (the nanoscale is defined as a spectrum of dimensions from about 1 nm to 100 nm); it has adopted the term NOAA to encompass all “Nano-Objects, their Agglomerates and Aggregates greater than 100 nm”.

Exclusions of different categories of materials

In addition to these grievances, there are additional questions about the new formulations adopted by the 2022 recommendation: for example, it does not take into account the questions and reservations of Anses, in particular¹¹Scientific and technical support note on “the development of a proposal for an updated definition of the term “nanomaterials” based on Recommendation 2011/696/EU”, Anses, 14 January 2022 and could lead to the exclusion of nano-objects previously considered as nanomaterials:

• the introduction of the term “solid” excludes gaseous and liquid particles, in particular emulsions and micelles (the latter, used for medical applications, have an increased capacity to pass certain biological barriers)
• the exclusion of “single molecules” could exclude from the definition of nanoplastics, fullerenes and, again, nanomicelles and lipid structures used as vectors
• the exclusion of nano-composites could be used by some brands to escape regulatory constraints on the grounds that their ingredients are complex compounds, in which several substances are present (for example, titanium dioxide nanoparticles coated with silica or grafted onto mica plates, used in particular in cosmetics).

Removal of the possibility of lowering the 50% threshold

The 50% rate of particles below 100 nm in number is identical to that of 2011 (and more than 333 times higher than the one defended by Scenihr (0.15%) in 2010¹² Cf. Scientific Basis for the Definition of the Term “nanomaterial”, SCENIHR, European Commission, 2010: Scenihr insisted on the knowledge of the size distribution of a nanomaterial and on the necessity of a distribution in number (more relevant than a distribution in mass defended by the industrialists). As a reminder, at the time, even the German industry did not ask for so much: it had argued for a rate of about 10% “only”).

However, the Commission had foreseen in 2011 that in case of concerns in terms of environmental or health risks this rate could be lowered below 50%. This is what the French authorities in particular have maintained¹³Cf.Nanomaterials – Evaluation of the national R-Nano declaration system, December 2020. The French High Council for Public Health (HCSP), in a 2018 report¹⁴Cf. Protéger les travailleurs et les personnes au voisinage de sites de production ou de manipulation de nanoparticules de dioxyde de titane, Haut conseil de la santé publique, 25 juin 2018, also recommended a 10% threshold by number for all substances and 1% by number in specific cases. ANSES¹⁵See https://www.anses.fr/en/content/seeking-more-protective-european-definition-nanomaterials also urges not to exclude from this definition certain nanomaterials that could be problematic for human health and the environment. According to the Agency, the definition must be as inclusive as possible. ANSES will publish an opinion, supported by a group of multidisciplinary experts, that will enrich the response to the European consultation (initially scheduled for 2022, the opinion is still not published in May 2023).

Industry federations, on the other hand, have opposed it¹⁶Cf.EU Plans to Review the Definition of a Nanomaterial, Nanotechnology Industries Association (NIA), December 3, 2020 and won their case during the revision of the recommendation, since the European Commission has removed this clause from the definition of 2022, which sets the rate at 50% without the possibility of lowering it.

This deletion now makes it possible not to consider as nanomaterials (and therefore not to regulate accordingly) substances of which 49% of the particles in number would be made up of particles below the 100 nm mark.

Are they doing away with health and environmental considerations?

Let’s take the particular case of cosmetics: the definition of the current Cosmetics Regulation does not include a threshold, the French authorities have used a threshold of 10% until now. Using a fixed threshold of 50%, would exempt from labeling and notification thousands of cosmetics containing nanoparticles, some of which are potentially dangerous for consumers.

What is the scope of this revised definition?

Towards transpositions with or without adaptation(s) in European regulations?

Will the revised definition be transposed to all Community regulations, regardless of their field of application? Not in the immediate future anyway: changing the definition of European regulations to bring them into line with the Commission’s definitional recommendation requires a specific co-decision review process that can take, in some cases, several years.

The Commission has clearly indicated its wish to see its revised recommendation become “binding”, from a legal point of view; it should therefore eventually be transposed into the regulation REACH (expected by the end of 2022) and other EU regulations with provisions on nanomaterials – starting with the cosmetics (work is in progress), then food, biocides and medical devices mainly (but what about the regulation on plant protection products as well as the draft revision of the directive on industrial emissions (IED) aimed at reducing emissions of polluting substances?)

Will this definition be transposed as is or with adaptations or management measures to minimize the health or environmental risks of materials “exhibiting nanoscale properties” but not covered by the revised definition recommendation?
The current revision of the Cosmetics Regulation¹⁷Cf. Towards a new nano definition in the future Cosmetics Regulation… yes, but which one?, VeilleNanos, July 13, 2022 were supposed to be, with REACH, the first “test” and could set a precedent. But time is flying and it seems that a delegated act aiming at copying the new definition into the Novel Foods regulation could come sooner than expected…

Health safety must prevail over legal consistency and certainty

The harmonization of the terminology was requested by the industry in order to put an end to the difficulties caused by the coexistence of different definitions which complicates the work of producers / importers / distributors: the latter complain about having to declare and label “nanomaterials” defined differently in various national registries (as r-nano in France), in REACH at European level and in sectoral regulations (food, cosmetics, biocides, medical devices, etc.). However, the harmonization of definitions must not be at the expense of public health and the environment. The problems associated with the coexistence of different definitions is a problem that could be solved upstream in the supply chain: if companies that produce and/or mix nanomaterials perform accurate and complete characterization of the substances and transmit the information correctly, downstream stakeholders can apply the appropriate definition to their sector and implement the appropriate labeling, registration and notification where applicable.

An operational and unique definition: “mission impossible”?

Defining what a nanomaterial is and revising the current definitions are complex problems, scientific but also highly political, with multiple implications for companies, lawyers and public authorities alike. The exercise is so perilous¹⁸For a synthetic analysis of the ins and outs of the debates around a single definition of nanomaterials, see the article by Georgia Miller and Fern Wickson “Disagreement Over Definitions Including Relevant Size, Size Distribution, Intentionality of Production, and Occurrence of Novel Properties” in Risk Analysis of Nanomaterials: Exposing Nanotechnology’s Naked EmperorMiller G and Wickson F, Review of Policy Research, 32(4): 485, July 2015. that some scientists even advise against it. For a long time, the French authorities also did not push for the revision of the definition at the European level: it is indeed on the previous one that was built the R-Nano device of annual declaration of the “substances in the nanoparticulate state”, obligatory in France since 2013.
NGOs are also sceptical¹⁹At the March 2014 CASG nano meeting, the European Environmental Bureau (BEE) criticized the Commission’s eagerness to launch this project: advances in the characterization and metrology of nanomaterials have certainly evolved since 2011, but not enough, according to the EEB, to justify a revision of the definition. This project, which is necessarily time-consuming and involves significant public expenditure, is less important and urgent than others, which were neglected by the Commission at the time, notably :
– the adaptation of the REACH annexes to nanomaterials (finally adopted in 2018, even if its implementation is still unfinished in mid-2020)
– the establishment of a Community register of nanoproducts on the European market..

Like Andrew Maynard before them²⁰Don’t define nanomaterials, Maynard A, Nature, 475, July 2011, French researchers consider that “an institutional definition is not a sine qua non condition for risk management and that the absence of definition or, in this case, the multiplicity of definitions from multiple sources, does not create a vacuum or exacerbate the difficulties of understanding risk management issues“. The researchers also consider that “a single definition, if it wants to remain operational, cannot embrace all the complexity of the questions related to the nano state of a particle. A scientific definition of nanoparticles and nanomaterials is not specifically useful to study whether or not they present a risk to health or more broadly to the environment“²¹CERTOP, The mobility of “nanos” risks, September 2014.

What are the strategies of the companies that produce and/or use nanos?

Industrialists may resort to avoidance strategies like the development of nanomaterials whose size and distribution in number can flirt with the thresholds (with a little more than 50% of the particles exceeding 110 nm for example) in order to escape the regulations while retaining the desired properties.

While manufacturers may have an interest in advocating for the narrowest possible definition of nanomaterials, in order to remove as many materials as possible from the regulations, market leaders may have an interest in ensuring that the definition and disclosures (particularly in the context of REACH) be very demanding, which would give them a competitive advantage over other companies with lesser means (technical and financial).

Another way to proceed, more in line with Corporate Social Responsibility (CSR), is to take part in a co-vigilance approach: anticipate the impacts of the massive use of these materials with specific properties of the nanometric scale and their release into the environment in order to give priority to eco-design of less dangerous materials (“safe by design”) and to minimize the risks throughout the life-cycle, sharing information with other actors upstream and downstream of the production chain (up to the final consumer), etc.

To be continued…