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

Abstract

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 anti-projection 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.

Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

“…Figure 1 a presents a picture of the FFP2 medical mask manufactured by Valmy (Mably, France) and kindly supplied by Grenoble Hospital (see previous work [ 8 ]). Those masks are composed of four layers, which will be characterized before and after irradiation ( Figure 1 b).…”

“…When applicable, the washing conditions were as follows [ 8 ]: 1 h and 12 min at a constant temperature (60 °C), using either pure water or neutral detergent, with “Ultimate mineral” surfactants (1 mL/kg) added, along with “Ultimate Forte” disinfectant based on perchloric acid and hydrogen peroxide (5 mL/kg). Ultimate detergent was chosen because it is commonly used in hospitals.…”

“…In case of the γ-ray irradiation performed at ArcNucleart, the dose rate was about 1.0 kGy h −1 , whereas in the case of the 10 MeV e-beam irradiation performed at IONISOS (Chaumesnil, France) using a Mevex A29 device (34 kW, 10 MeV), the dose rate was several hundreds of kGy min −1 . When applicable, the washing conditions were as follows [8]: 1 h and 12 min at a constant temperature (60 • C), using either pure water or neutral detergent, with "Ultimate mineral" surfactants (1 mL/kg) added, along with "Ultimate Forte" disinfectant based on perchloric acid and hydrogen peroxide (5 mL/kg). Ultimate detergent was chosen because it is commonly used in hospitals.…”

“…Since sterilization is usually performed in the medical field using either γ-rays [ 5 , 6 ] or e-beam [ 7 ] irradiation, it initially seemed very interesting to sterilize masks using this protocol. Moreover, for acceptance purposes, washing prior to the sterilization process was found to be unavoidable and has already been addressed in recent papers [ 8 ]. However, it is well-known that irradiation induces changes in organic materials at the molecular, macromolecular and microscopic levels.…”

Impact of washing parameters on bacterial filtration efficiency and breathability of community and medical facemasks

“…Although initially designed as single use, studying the feasibility of the reuse of the medical face masks also appears interesting for both environmental and supply reasons. Some studies have shown that medical face masks are capable of being reused after 10 washing cycles 16 , 17 .…”