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Conceptual interpretation of nanoforms in EU Regulation SDS

Posted Date:2024/12/26

Nanoforms

The revised Annex VI of REACH introduces the concept of “nanoform” into the Regulation. It establishes the principles that all the nanoforms of the substance that are covered by the registration have to be reported in the registration dossier. By derogation to this principle, the revised Annex VI enables registrants to report several nanoforms together if certain conditions are met. The following sections will explain the criteria and conditions to report nanoforms (section 3.1) and sets of nanoforms1 (section 4).

Nanoform concept

According to Annex VI of the REACH Regulation, a “nanoform” is a form of a natural or manufactured substance2 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 also by derogation fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm. The concepts and terms used for nanoform in this guidance follow the concepts and terms used in the European Commission’s recommendation on definition of nanomaterial as outlined and explained in the Joint Research Centre (JRC) Report ‘An overview of concepts and terms used in the European Commission’s definition of nanomaterial’ . A second JRC report (Identification of nanomaterials through measurements) aims to support the implementation of the nanomaterials definition.

A nanoform must be characterised in accordance with Annex VI section 2.4 of REACH. A substance may have one or more different nanoforms, based on differences in the parameters in points 2.4.2 to 2.4.5 (size distribution, shape and other morphological characterisation, surface treatment and functionalisation and specific surface area of the particles).

Variation of one or several of the characterisers defined in section 2.4.2-2.4.5 results in a different nanoform, unless such variation results from a batch-to-batch variability. A batch-to- batch variability only results from the variation of parameters inherent to a manufacturing process that is defined by a series of process parameters (e.g. starting materials, solvents, temperature, order of manufacturing steps, purification steps, etc.). In this context, the process parameters can be modified only to minimise the batch-to-batch variations. Any other modification in process parameters results in a different nanoform.

Different manufacturing processes may result in almost identical characterisers. These different nanoforms can be registered as part of a set of nanoforms. In such cases, the creation of a set of nanoforms will be simple as the variation of the different characterisers will be small (see section 4). The smaller the variation the easier the justification to cover different nanoforms in the same set.

Sections 3.1.1 to 3.1.4 below provide explanations on the determination of nanoforms in practice for each parameter set out in section 2.4.2-2.4.5 of the revised Annex VI of REACH. Each of the sections explaining how nanoforms are identified includes a subsection on the characterisation requirements for an individual nanoform for the parameter described. For the sake of clarity, the explanations are given for each specific parameter. However, when considering what constitutes a different nanoform, the four parameters must be considered  jointly.