FICHE D’INFORMATION SUR LA DÉFINITION DES NANOMATÉRIAUX

This fact sheet by the Center for International Environmental Law (CIEL) discusses the critical need for a precise legal definition of nanomaterials to ensure effective risk assessment and management. It examines the technical challenges of defining these materials based on size or properties and analyzes the current regulatory landscape, focusing on the European Union's efforts to establish a horizontal definition amidst industrial and scientific controversy.

• A precise legal definition of nanomaterials is essential for establishing risk assessment systems and management measures. Definitions that are too restrictive may allow materials to enter the market without proper evaluation, while overly broad definitions may subject irrelevant materials to unnecessary procedures.
• Defining nanomaterials based on size is the most common global approach, typically using a range of 1 to 100 nm. However, this method faces technical difficulties because the 100 nm threshold is considered arbitrary rather than scientific, and most nanomaterials have non-uniform particle sizes that require distribution curves rather than fixed values.
• Approaches based on nano-specific properties are problematic because some nano-scale properties are also found in bulk materials, and some toxicity mechanisms depend solely on size regardless of specific properties, meaning such materials might escape regulation if only properties are considered.
• The European Union is the only jurisdiction with a horizontal legal definition of nanomaterials, though it lacks harmonization across sectors. The 2011 European Commission recommendation defines a nanomaterial as a natural, accidental, or manufactured material containing free particles, aggregates, or agglomerates where at least 50% of particles in the size distribution have one or more external dimensions between 1 nm and 100 nm.
• The EU's recommended definition is contested by industry actors who argue it is too costly to implement due to the need for expensive measurement techniques for every batch and that the 50% threshold is too broad. Conversely, some scientists and civil society groups argue the definition is too restrictive and suggest a threshold as low as 0.15% to ensure safety.
• Technical implementation of the EU definition is hindered by the lack of standardized analysis methods. Key issues include the difficulty of measuring non-spherical particles using tools designed for spherical diameters, the risk of damaging particles when dispersing aggregates, and the questionable accuracy of converting mass or volume distributions into numerical distributions.
• Global definitions vary, leading to legal uncertainty. The ISO defines a nanomaterial as having at least one external dimension at the nanoscale or an internal/surface structure at the nanoscale. The US lacks a regulatory definition, with the EPA and FDA using different working definitions, while Health Canada uses a working definition that includes materials with nano-scale properties even if they fall outside the 1-100 nm range.

APA

Center for International Environmental Law (2014). FICHE D’INFORMATION SUR LA DÉFINITION DES NANOMATÉRIAUX. https://www.ciel.org/wp-content/uploads/2016/08/Nano-Definition-Factsheet-French.pdf

Chicago

Center for International Environmental Law. FICHE D’INFORMATION SUR LA DÉFINITION DES NANOMATÉRIAUX. 2014. https://www.ciel.org/wp-content/uploads/2016/08/Nano-Definition-Factsheet-French.pdf.

Wikipedia

{{cite report |author=Center for International Environmental Law |title=FICHE D’INFORMATION SUR LA DÉFINITION DES NANOMATÉRIAUX |date=November 2014 |url=https://www.ciel.org/wp-content/uploads/2016/08/Nano-Definition-Factsheet-French.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{centerforinternationalenvironmentallaw2014fiche, author = {{Center for International Environmental Law}}, title = {{FICHE D’INFORMATION SUR LA DÉFINITION DES NANOMATÉRIAUX}}, institution = {Center for International Environmental Law}, year = {2014}, month = nov, url = {https://www.ciel.org/wp-content/uploads/2016/08/Nano-Definition-Factsheet-French.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }