Reuse of medical face masks in domestic and community settings without sacrificing safety: Ecological and economical lessons from the Covid-19 pandemic

The need for personal protective equipment increased exponentially in response to the Covid-19 pandemic. To cope with the mask shortage during springtime 2020, a French consortium was created to find ways to reuse medical and respiratory masks in healthcare departments. The consortium addressed the complex context of the balance between cleaning medical masks in a way that maintains their safety and functionality for reuse, with the environmental advantage to manage medical disposable waste despite the current mask designation as single-use by the regulatory frameworks. We report a Workflow that provides a quantitative basis to determine the safety and efficacy of a medical mask that is decontaminated for reuse. The type IIR polypropylene medical masks can be washed up to 10 times, washed 5 times and autoclaved 5 times, or washed then sterilized with radiations or ethylene oxide, without any degradation of their filtration or breathability properties. There is loss of the antiprojection properties. The Workflow rendered the medical masks to comply to the AFNOR S76-001 standard as “type 1 non-sanitory usage masks”. This qualification gives a legal status to the Workflow-treated masks and allows recommendation for the reuse of washed medical masks by the general population, with the significant public health advantage of providing better protection than cloth-tissue masks. Additionally, such a legal status provides a basis to perform a clinical trial to test the masks in real conditions, with full compliance with EN 14683 norm, for collective reuse. The rational reuse of medical mask and their end-of-life management is critical, particularly in pandemic periods when decisive turns can be taken. The reuse of masks in the general population, in industries, or in hospitals (but not for surgery) has significant advantages for the management of waste without degrading the safety of individuals wearing reused masks

Influence of debinding and sintering conditions on the composition and thermal conductivity of copper parts printed from highly loaded photocurable formulations

International audienceMetal 3D printing based on the photopolymerization reaction (Digital Light Processing DLP) of an organic matrix in which metal particles are embedded is a developing technology. This technology requires a step of resin removal and densification by sintering to obtain a metal part. This process has been applied to copper. Photocurable formulations with a high loading rate of copper powder of 60 vol.% were developed and suitable for DLP printing with thicknesses>25 µm. Debinding and sintering cycles were investigated on specimens fast cured by gamma irradiation to save materials and time. A debinding in air at 400 °C and sintering in hydrogen lead to a C content of 0.018 wt.%, similar to the raw copper powder and slightly higher oxygen content. The low thermal conductivity of 250 W·m-1·K-1 highlighted the harmful effect of phosphorus from the powder and photoinitiators such as BAPO. The C and O contents and the thermal conductivity measured on copper parts printed by DLP confirm the results obtained on specimens cured by gamma irradiation

ARC-NUCLÉART – 50 years of radiation conservation of historical objects

Artykuł powstał z okazji 50 rocznicy utworzenia radiacyjnego laboratorium badawczego i profesjonalnej pracowni konserwacji dzieł sztuki ARC-NucleArt (Atelier de Recherche et de Conservation Nucléart). Przypomniano historię tej zasłużonej dla ratowania obiektów historycznych placówki. Jest ona pionierem w zastosowaniu technik radiacyjnych do dezynsekcji, dezynfekcji i konsolidacji. Krótko omówiono zasady wykorzystania promieniowania jonizującego do ratowania zagrożonych insektami, grzybami i bakteriami obiektów archeologicznych i dzieł sztuki. W przeglądzie literaturowym odsyłamy do publikacji podsumowujących światowe badania w zakresie radiacyjnej konserwacji różnych materiałów.The article was created on the occasion of the 50th anniversary of the creation of the radiation research laboratory and professional art conservation studio ARC-NucleArt (Atelier de Recherche et de Conservation Nucléart). The history of this institution merited for saving historical objects was recalled. She is a pioneer in the application of radiation techniques for disinfestation, disinfection and consolidation. The principles of using ionizing radiation to rescue archaeological sites and works of art endangered by insects, fungi and bacteria are briefly discussed. In the literature review, we refer to publications summarizing the global research in the field of radiation conservation of very different materials

Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

International audienceIn the context of the SARS-CoV2 pandemic and because of the surgical and FFP2 mask (equivalent to the American N95 masks) shortages, studies on efficient sterilization protocols were initiated. As sterilization using irradiation is commonly used in the medical field, this method was among those that were evaluated. In this work, we tested irradiation under vacuum and under air (under both γ-rays and e-beams), but also, for acceptance purposes, undertook washing prior to the e-beam irradiation sterilization process. This article deals with the modifications induced by the sterilization processes at the molecular and the macromolecular scales on an FFP2 mask. Fourier transform infrared spectroscopy in attenuated total reflectance mode, size-exclusion chromatography and thermal-desorption-gas chromatography-mass spectrometry were used to characterize possible damage to the materials. It appeared that the modifications induced by the different sterilization processes under vacuum were relatively tenuous and became more significant when irradiation was performed using γ-rays under air

La biopile enzymatique à glucose/oxygène

Une biopile enzymatique implantable est un dispositif produisant du courant uniquement à partir du glucose et de l’oxygène naturellement et constamment présents dans l’organisme. Les enzymes présentes aux électrodes oxydent le glucose et réduisent l’oxygène, ce qui génère un flux d’électrons dans un circuit électrique associé. Cette microcentrale électrique, qui peut fournir une tension de presque un volt, pourra alimenter sur une longue période la future génération de robots implantables. Tout dispositif médical implantable doit être stérilisé avant son implantation. Comme le principe actif de cette biopile est composé d’enzymes, la question de la stérilisation de ce nouveau type de dispositif s’est posée