In an article published on March 30, 2017 the European Commission’s (EC) Joint Research Centre (JRC) informs about its contribution to the development of “a low cost and highly efficient screening strategy” for identifying nanomaterials. Several EU regulations, e.g. the cosmetic products regulation, novel foods regulation, or plastic food contact materials (FCM) regulation, require information on nanomaterials as well as their safety assessment, the JRC highlights. Therefore, it is important to reliably determine “whether a material actually is a nanomaterial, and whether specific regulatory provisions apply,” the JRC further illustrates. According to the EC’s recommended definition, a nanomaterial “should consist for 50% or more of particles having a size between 1 nm-100 nm.” The EC’s nano-definition is currently under review and planned to be updated soon (FPF reported).
One method to measure particle sizes from 1 nm up to several hundred nm is to employ transmission electron microscopy (TEM). This can be “costly and time-consuming” and involves “elaborate sample preparation,” the JRC explains. Another possibility for identifying nanomaterials is to determine their volume specific surface area (VSSA). This can be achieved by applying a “well-known, low cost and standardized method” to dry powders without additional sample preparation. The method involves “the adsorption of a monolayer of an inert gas on the surface of the particles,” the JRC outlines.
In the scope of the EU project NanoDefine (FPF reported), the JRC helped evaluate the level of agreement between the nano-classifications obtained by employing TEM and VSSA on various particulate substances. VSSA was found to be an efficient screening method to distinguish between nano- and non-nanomaterials. Therefore, the NanoDefine consortium recommends a screening strategy relying on VSSA to be “included in a technical guidance for implementation of the [EC’s] nanomaterial definition.”
JRC (March 30, 2017). “Nanomaterials or non- nanomaterials.”
Wohlleben, W. et al. (2017). “Reliable nanomaterial classification of powders using the volume-specific surface area method.” Journal of Nanoparticle Research 19:61.