Engineered nanomaterials have established themselves as a staple in industry, and have paved the way for the development of new products. On one hand, their size and specific, highly chemically reactive surfaces make nanomaterials promising candidates in terms of their range of applications. On the other, its virtually impossible to make any universally valid statements on their potential effects on human beings or the environment.
The difficulty of assessing the safety of these innovative materials, which are often made of complex compositions, is compounded by the fact that not only the chemical species and the amount/dosage but also further physical-chemical parameters like the particle shape, structure, specific surface characteristics, size and size distribution are important aspects. As such, it is currently extremely difficult to take into account potential transformation processes like the aggregation into larger clusters or dissolution into ionic components, and to differentiate between nanomaterial-specific and nonspecific effects. In addition, nano-scale reference materials and nanomaterials that can be found in complex environmental samples are currently in short supply.
Accordingly, the standardized methods and testing techniques currently in use must be refined and adapted. In response to these challenges, this article proposes new approaches to differentiating between synthetic nanomaterials and their naturally occurring counterparts, illustrating them on the basis of an environmentally relevant sample application.