Nanoplastics are becoming a familiar term due to increased discussions on plastic pollution, yet they have not been as well described as engineered nanomaterials. This Nanopinion posted on the website of the EU Observatory on Nanomaterials (EUON) aims to bring some clarity to the debate.
The size range regarding nanoplastics spams from 1 to 1000 nm, though some authors prefer to set an upper limit of 100 nm. The article authors explain that nanoplastics result from the fragmentation of larger items, making it challenging to identify in complex media, owing to the uncertainties on their composition. The article refers to these as secondary plastics.
However, most of the ecotoxicity studies currently ongoing used primary nanoplastics designed in the laboratory, with defined properties. Even if far from the real situation, such studies may still be used as a model to define the criteria to evaluate which physico-chemical properties of nanoplastics are the most relevant for risk assessment. The article proposes some relevant criteria such as composition, chemical leaching, hydrophobicity, or colour.
The full Nanopinion can be read at this link.