Nanomaterials are materials with at least one of measurements between one and one hundred nanometers. A nanometer (i.e., one millionth of a millimeter) is fifty thousand times smaller than the diameter of a human hair, and so we are in a universe invisible to the human eye. It is a solid whose surface is one-centimeter square. If we divide this solid into millions of particles, the surface increases by a millionfold, and hence there is a huge increase in surface area and thus a better use of their properties, with a drastic reduction in the quantity used. Nanomaterials have applications in various fields - electronics, pharmaceuticals, energy, environment, food, packaging, textiles, cosmetics, etc. - which have not yet been fully explored still today.
The physical properties of materials and nanocomposites in particular also affect foods, in an orientation that tends to favor physical rather than chemical treatments, with the latter being increasingly opposed by the public. The possible food applications of nanomaterials are diverse, covering also food and especially their packaging for now.
Nanomaterials can in theory be used as food additives, i.e., for specific technological purposes (anti-caking agents, colorings, etc.). At the moment, no nanomaterials have been introduced as additives, but some additives used for a long time (such as silicon and titanium dioxides) contain a part of their constituents in nanoform. Moreover, the presence of nanomaterials in national and EU food production in this period is not significant and is limited to nanoform fractions.
Nanomaterials are useful in the packaging industry and in preservation. Added to plastics, they improve storage, thanks to the enhanced barrier effect. One example is the silver nanoparticles whose properties are exploited to form antibacterial surfaces that can extend the life of packaged foods without using chemical molecules.
However, knowledge is still incomplete regarding the effects that nanoparticles may have on the body when ingested through food. Important research is being carried out on this very point that will clarify existing doubts. The EU is taking a very cautious approach pending scientific research developments.
According to the European Union regulations in force, food containing nanomaterials fall into the category of "novel food" and therefore their use must be explicitly authorized. Their possible authorization is subject to evidence of their effectiveness and above all their safety for consumers, which must be assessed by the European Food Safety Authority (EFSA).
Currently, no nanomaterials have been proposed as additives, but certain additives in use for a long time (such as silicon dioxide and titanium) have been identified as containing a portion of the constituent particles in nanoform and the production process used is under examination by the EFSA in the context of a program to re-evaluate authorized additives.
Whatever the reason for their use (as ingredients or as additives), the presence of nanomaterials in food must be indicated on the labels (with the word "nano" in brackets after the name of the ingredient).
Today few nanomaterials have been authorized in the European Union as additives for plastics in contact with food, for which the EFSA has verified the absence of migration into the food. In other parts of the world, nanotechnology is relatively more common and the EU is on the alert to prevent the importation of products that use them, if the same use is not authorized in Europe.
It is, however, of paramount importance to inform consumers about nanomaterials to report any problems that might be related to their use and, where necessary, the appropriate precautionary measures to be adopted.