TU Delft works on reusable surgical masks with Reinier de Graaf and VSM

News - 20 March 2020 - Webredactie 3ME

In the fight against the 'Corona shortage’ of face masks, John van den Dobbelsteen and Tim Horeman, researchers at the Department of BioMechanical Engineering department, and with lab manager Rob Luttjeboer, developed a successful way to test reused sterilised surgical masks and surgical masks made of new materials.

In collaboration with Bart van Straten, director of Van Straten Medical, they also tested a new way of sterilising various surgical masks from Sint Franciscus Gasthuis, LUMC and the Reinier de Graaf Hospital. The used surgical masks were resterilised according to a specific protocol at 121 degrees and tested at TU Delft and the Reinier de Graaf Hospital. The results are very promising. For example, the researchers have shown that sterilising FFP1 and FFP2 face masks by means of steam is not impossible after all, in contrast to earlier reports in the media. Also, with the help of newly constructed measuring systems, new materials have been selected that can serve as an alternative in surgical masks should they run out.

“A visual inspection of the surgical masks after sterilisation shows no distortion, permeability or paper damage. We have also benchmarked the surgical masks with new surgical masks. The only thing we do notice after the first tests is that the elastic band seems vulnerable after resterilisation with steam. However, this can easily be replaced. In any case, these positive results could be a nice alternative for the shortage of surgical masks and the potentially high prices as a result of the coronavirus,” says Sing Dekker, expert in sterile medical devices (DSMH) at the Reinier de Graaf Hospital.

Watch the video:

Update on 24/03/2020: Results published

The researchers published the research results via the TU Delft Repository.

Sterilization of disposable face masks by means of dry and steam sterilization processes: an alternative in case of acute mask shortages due to COVID-19

Reuse of face masks to combat mask shortages due to coronavirus
The Covid-19 pandemic and its rapid spread has led to an impending shortage of face masks and other personal protective equipment. In collaboration with TU Delft, the Sint Franciscus Gasthuis and several other hospitals, we have tested a method to sterilise used face masks. The test results are consistent with those of new face masks.

Sterilisation of face masks: Express service
Van Straten Medical/CSA Services De Meern is offering its support to hospitals, public health services (GGD) and other healthcare institutions (including nursing homes) in need. Operating under the name GreenCycl, they collect and inspect face masks, put them in laminated packaging, sterilise them in accordance with the proven method and return the masks – in laminated packaging – to the institution. They are also on hand to help healthcare institutions set up their own sterilisation processes on site. Institutes are advised to set up a special route to protect personnel against Covid-19. More information: info@greencycl.nl, +31 (0) 30 602 38 28, +31 (0) 30 602 38 30. Rijnzathe 2, De Meern-Utrecht.

It is advisable to test the masks once the sterilisation process has been set up. This also applies to masks made in-house. We also recommend that you follow Article 5 of the MDR and to perform a risk analysis of your custom-made medical devices. You can get the face masks tested using the TU Delft testing equipment or that of Van Straten Medical/CSA Services in De Meern. The tests are carried out on masks that have been sterilised using dry and steam sterilisation processes at 121⁰C. For steam sterilisation, the face masks are first put in laminated packaging (Note: In our sterilisation method, sterilising at 134 ⁰C results in material deformation, which may lead to degradation of the material and pore size.)The final assessment decision regarding safety lies with the Sterile Medical Devices Experts (DSMH) at the hospitals.