Nanomaterials are a complex matter. Right now there is no uniform definition which makes it possible to identify nanomaterials in a uniform manner.

In October 2011 the European Commission published its recommendation for the definition of a nanomaterial (2011/686/EU): a nanomaterial is a natural material, formed accidentally or deliberatly engineered, which contains particles in an unbound state or as an aggregate or an agglomerate. 50% of these particles in the particle size distribution based on numbers need to possess  one or more dimensions within the range of 1 to 100 nm (nanometres).

The specific surface of the material can be an extra parameter: a material whose specific surface exceeds 60 m²/cm³ is considered as nanometric.

The proposed definition of the European Commission does not necessarily cover the same nanomaterials as the definitions with a scientific purpose or aiming at standardization (like for example the definition of ISO standards). It can also be tailored in the specific legislations in which it is used.

But concretely, what does it correspond to?

Nanomaterials contain particles of very small sizes, inferior to 100 nm. As an order of magnitude, if we compare the diameter of a one eurocent coin to a nanometre, one meter would be tantamount to the diameter of the earth. A huge scale that gives an idea of the minute size of nanomaterials. Their very small size confers them characteristics that are very different to those of the same materials of larger size. Should we take the example of gold, it has a yellowish colour and is inert in its macroscopic shape (visible to the naked eye). But in its nanometric shape, it is an excellent, highly reactive catalyst (activator of chemical reaction) and has a reddish colour.

Another important aspect of these nanomaterials is their specific surface, i.e. the surface of the material in relation to their mass or volume. For instance, zeolites are nanometric materials with many porosities. They are particularly used in washing powers due to their ion ingressing power, which reduces the cleaning capacity of the detergent. This nanometric porosity is so important that a very low quantity is necessary to ingress a large number of calcium ions. On average, 1 gram of this material has a surface in the order of 850 square meter, i.e. more than 4 tennis grounds!

Is there a list / an official census of nanomaterials?

However, a minority of the nanomaterials are subject to registration through the REACH (chemical substances) regulation. More information is available on the website of ECHA (European Chemicals Agency).

In its actual format (spring 2016), the REACH is not adapted to the registration of nanomaterials and the registrations actually made contain little information regarding the specific features of nanomaterials.

On the European level there exists currently no registration specifically aimed at  nanomaterials. A couple of individual member states have adapted their legislation or are planning to adapt it to enable the registration of nanomaterials.

The first mandatory reporting pertaining to the French market was introduced in 2013. Some of the information thus collected will be publicly available and partly useful to understand the nature of what is found on the Belgian market.

In 2012, the Danish Environmental Protection Agency launched a number of initiatives for better control of nanomaterials. A summary of these initiatives is included in the report "Better control of nanomaterials".

Since 2016, Belgium has also launched its own register for substances produced in nanoparticular state in order to follow the evolution of the Belgian market and to be in a position to take fast action should it be needed.

In 2016, also Sweden took the first legal steps to make the registration of nanomaterials compulsory.

Other, non-official, databases, exist along with various studies (see the "Links" section).