The Department of Energy Systems and Environment (DSEE) at IMT Atlantique is contributing its expertise as part of the French scientific consortium aiming to find a solution for recycling used masks. This consortium brings together about twenty teams*, including the IMT Atlantique team, and has been working for almost a month to test the potential solutions on the test benches in the research lsbs on the Nantes campus ... with promising initial results!
Could surgical and FFP2 masks be reused safely? This is the idea put forward by Philippe Cinquin, professor at the University of Grenoble-Alpes, director of the TIMC-IMAG laboratory. Dr. Cinquin coordinates the consortium (read his interview - in French - in the CNRS journal) composed of doctors, virologists, hygienists, physicists and materials and industrial engineers, from CNRS and CEA laboratories. Very early on, he turned to the team of researchers working on aerosol filtration at the GEPEA laboratory (UMR CNRS 6144), recognized for its expertise in filtration applied to air treatment, with a particular focus on air quality related to concentrations of particles and microorganisms.
Illustrations of experimental devices in the field of aerosol filtration expertise.
While respecting the measures related to the government's general stay-at-home order, a team made up of three researchers and two technical staff members has set up a test bench within the DSEE that is very close to the conditions of the standard applying to surgical masks to test their performance after treatment. The first filtration tests began on March 19th and continued two days a week. "The team has already characterized the filtration performance of seven mask models (surgical and FFP2) - new, new-treated and used-treated - with two or even three repetitions per sample" explains Yves Andres, head of the DSEE. Dr. Andres emphasized "how decisive the contribution was of the technical personnel urgently called upon to develop technical solutions and set up the experimental conditions, and I would like to thank Yvan Gouriou and François-Xavier Blanchet for their involvement."
Sterilization, irradiation, washing...
The challenge is to "eliminate the microbial load of the masks after the first use, while ensuring that their level of performance is maintained" says Laurence Le Coq, Director of Research and Innovation at IMT Atlantique. "It's not a question of putting a mask in the washing machine. A whole protocol has to be devised to make them reusable while preserving their intrinsic qualities, so that they meet standards and offer the same level of protection as a new mask for those who wear them."
"Mask performance level is verified by comparing the filtration effectiveness of new and treated masks with respect to particles whose diameter varies from 0.3 to 3 µm, as well as the maintenance of mask permeability" says Associate Professor Aurélie Joubert of the DSEE department.
Different techniques are being considered by the consortium: treatment by moist heat in an autoclave (a tool that allows sterilization) at 121°C for 50 minutes; exposure to ethylene oxide, known for its biocidal properties; and heating to 70°C in dry heat or in water, irradiation by gamma or beta radiation, etc. The first tests have made it possible to verify the effectiveness of some of these techniques on surgical masks, but not on FP2 masks. For the moment, the researchers remain very cautious, even if "among the promising treatment options, heat treatment with dry heat seems to demonstrate a certain effectiveness in maintaining mask performance", explains Laurence Le Coq.
The interdisciplinary consortium has joined the international "ReUse" task force with which the results will be shared. Once the results have been validated by the French National Agency for the Safety of Medicines and Health Products (ANSM), the logistics of implementing recycling solutions as close as possible to healthcare personnel will have to be considered.
* The consortium : Philippe Cinquin (TIMC (Unité CNRS-UGA-G-INP-VetagroSup)/ CIC-IT1406 (Inserm/DGOS/CHU de Grenoble/ Université Grenoble Alpes)), Jean Pierre Alcaraz (TIMC), Caroline Landelle (TIMC /Service d’Hygiène, Pôle de Santé Publique, CHUGA), Catherine Guimier-Pingault (Service de Stérilisation, Pôle Pharmacie CHUGA), Laurent Cortella (ARCNUCLEART, CEA-Grenoble / NIMBE, Unité CEA, CNRS, Université Paris-Saclay, CEA Saclay / Des-Service d'Étude du Comportement des Radionucléides (SECR), CEA, Université Paris Saclay), Laurence Le Coq (IMT Atlantique, GEPEA), Aurélie Joubert (IMT Atlantique, GEPEA), Yves Andrès (IMT Atlantique, GEPEA), Sandrine Chazelet (INRS Nancy), Sophie Rouif (IONISOS & STERYLENE), Muriel Ferry, Sylvaine Le Caër et Stéphane Esnouf (ARCNUCLEART, CEA-Grenoble / NIMBE, Unité CEA, CNRS, Université Paris-Saclay, CEA Saclay / Des-Service d'Étude du Comportement des Radionucléides (SECR), CEA, Université Paris Saclay), Laurent Heux (Cermav), Jean-Paul Brion (PUMA), Olivier Epaulard (PUMA), Sophie Silvent, Isabelle Bourdry et Maud Barbado(CIC-IT1406), Valentin Paran (TIMC), Théophile Tiffet (TIMC, CIC-IT406), Max Maurin (Service de bactériologie, CHUGA), Olivier Terrier (Equipe VirPAth, Centre International de Recherche en Infectiologie (CIRI), Unité INSERM/ CNRS/ENS Lyon/ Université Claude Bernard Lyon 1), Patrice Morand, Pascal, Poignard et Raphaële Germi (Service de Virologie, CHUGA), Daniel Garin (ARTELIA), Abdelaziz Bakri, Nawel Khalef et Joël Gaffé (TIMC), Camille Ducki (Direction de la Recherche en Santé et Innovation, CHUGA), Jean-Michel Nguyen (CHU de Nantes), Yves Dubief (LEGI, unité CNRS- UGA), Dominique Thomas (LRGP, unité CNRS/Université de Nancy), Marine Beaumont (CIC-IT1433, unité INSERM-CHU Nancy), Jacques Felblinger (CIC-IT1406), Jean-Luc Bosson et Alexandre Moreau-Gaudry (TIMC et CIC-IT1406)
- the promising results of a French consortium [April 2020 - ARCHY Worldys]
by Pierre-Hervé VAILLANT