Development of a rapid plasma decontamination system for decontamination and reuse of filtering facepiece respirators

The COVID-19 pandemic has caused a high demand for filtering facepiece respirators (FFRs), which has brought global challenges in sustaining the supply chain for FFRs. Because respirators are basic personal protective equipment to protect frontline healthcare workers against COVID-19, the chronic, global shortage of N95/N99 masks is one of the most urgent threats to our collective ability to save lives from the coronavirus. The reuse of masks may need to be considered as a crisis capacity strategy to ensure continued availability even though most of the masks are considered one-time use. Moreover, environmentalists warn that single-use masks add to the glut of plastic pollution, threatening the health of oceans and marine life. In this study, we develop a method to decontaminate respirators to reuse filtering facepiece respirators. Samples of SARS-CoV-2 are applied to the 4 × 4 cm² samples of FFP2 and FFP3 respirator materials. The filtration efficiency of plasma treated samples is measured using a planar particle image velocimetry technique with a neutrally charged polydisperse aerosol particle of NaCl. The measured viral decontamination and filtration efficiencies show that the developed plasma decontamination system can achieve a 4-log reduction for the coronavirus without reducing the filtration efficiency of masks after 5-min plasma exposure. The developed plasma decontamination system demonstrates the feasibility to tackle the acute shortages of FFRs in many countries and their environmental and economic burdens against discarding reusable masks.