Quality Testing of FFP2 Masks and Filter Materials

Testing the fit of a face mask with the help of a dummy head Copyright: © Maik Tepper

In collaboration with external partners, researchers from RWTH Aachen University have developed a three-step test process for FFP2 masks and filter materials. Over the last few weeks, a large number of masks have been assessed at AVT, the Aachen Chemical Engineering departments.



John Linkhorst



+49 241 80 29966



“Since the beginning of the coronavirus pandemic, hospitals have been in need of significantly more FFP2 masks. Currently they are purchasing such masks from new suppliers. With our initiative, we want to contribute to making sure that medical staff are equipped with high-quality masks. Therefore, within a few days, we have developed a test procedure which supports hospitals in their quality control activities,” explains Dr. John Linkhorst, senior engineer at the RWTH Chair of Chemical Process Engineering. “Initially, our campaign was limited to a collaboration with Uniklinik RWTH Aachen. Now we are also supporting hospitals throughout Germany, as well as other institutions, including fire brigades and emergency medical services.”

Three-Step Test Process

The test procedure is based on the relevant DIN standards and subjects the masks to an overall quality test. AVT is testing the masks in three stages: First, the fit of the mask is assessed in terms of fit using a dummy head. A good fit ensures that the virus does not pass the mask into the airways. Subsequently, the filtration performance of the mask is tested. Finally, the properties of the actual filter material are checked to identify possible defects.

"We can easily determine whether high-quality filter material has been integrated into a well-fitting mask without defects. We inform the hospitals about our results as soon as possible, and based on our assessment, they can decide on whether to continue to use the masks," says environmental engineer Anna Kalde, a research associate at DWI, who has been organizing the mask tests together with Michael Alders.

As Professor Matthias Wessling, Chair of Chemical Process Engineering and member of the Scientific Board of DWI, explains: "From basic research in the area of filter materials, 3D printing, the construction of prototypes and pilot plants to the development of medical devices, we cover a broad field of research at AVT, RWTH’s Chemical Engineering departments. That's why we are used to working together in interdisciplinary teams. Our highly motivated team transfers these competencies into the project." Wessling, who is also Vice-Rector for Research and Structure at RWTH, has been awarded the Gottfried Wilhelm Leibniz Prize in 2019. "We are still receiving many requests, so we will continue to test," says Wessling.

In addition to the Chair of Chemical Process Engineering and the DWI Leibniz Institute for Interactive Materials, the Institute for Occupational, Social and Environmental Medicine at Uniklinik RWTH Aachen has been involved in the project.

The support provided by regional partners contributed significantly to its success. TSI GmbH provided an aerosol generator and detector for the test bench, ZUMOLab enabled the storage of data by providing control software and a measuring box, and FURTHRresearch made available its data management software and accompanied the tests with its expertise. FURTHRresearch and ZUMOLab are spin-offs from RWTH Aachen University.