We test the presence of nanofibers for the Customs Administration of the Czech Republic

The Customs Administration of the Czech Republic established cooperation with the Laboratory of Advanced Nanobiomaterials of Czech Technical University UCEEB in order to confirm or refute the declaration of the presence of nanofibers in personal protective equipment (e.g. respirators or masks) determined by the manufacturer.

The Customs Administration of the Czech Republic checks, among other things, whether the product is accompanied by documentation in accordance with applicable legal regulations and is marked or provided with a specified marking, or whether the product meets special product safety requirements. In the event that the inspected products do not meet certain requirements, the Customs Administration of the Czech Republic forwards its findings to the competent supervisory authority with a request for a binding opinion, which is decisive for the release of the goods into the customs regime of free circulation.

The goal of the analysis is to verify the presence of nanofibers in the delivered product samples. The results of the analyzes serve the Customs Administration of the Czech Republic to take further steps against importers of goods of questionable quality and to prevent the introduction of low-quality products on the market. In this way, seven samples were already tested by the scanning electron microscopy method in the Laboratory of Advanced Nanobiomaterials of the Czech Technical University UCEEB.

The resulting report contains images taken by a scanning electron microscope from each layer of the tested sample. All layers analyzed were imaged from both sides to rule out the possibility of error in not analyzing a layer of nanofibers that could not be separately separated from any of the other layers in the sample.

If nanofibers were found on one side of the microfiber layer, each side was analyzed separately. If the nanofibrous structure was not present, several images were taken of each layer from different areas so that the analysis of the diameter of the fibers was as accurate as possible.


Sample test sample


Nanofibrous layer in the examined sample at two magnifications