Viral Filtration Efficiency: Impact of Washing on Reusable Masks
VINCENT BROCHU, Nathalie Turgeon, Marc Veillette, Caroline Duchaine, Université Laval
Abstract Number: 308
Working Group: Bioaerosols
Abstract
Introduction
During the Sars-CoV-2 pandemic, single-use masks were heavily used to reduce the spread of the virus in the community. From an environmental perspective, reusable masks present a potential alternative to single-use ones. However, the effect of washing on the viral filtration efficiency of reusable masks is not well documented.
Methods
On a test bench simulating the dispersion of viral aerosols ranging from 29 to 5000 nm, particulate, and viral filtration efficiencies were evaluated for five reusable masks (Frëtt Solutions, Quebec, Canada): eAir, ePro, eTech V, eMed, and eMed 3. Those patented masks are made with polypropylene layers. Masks were placed one at a time on the test bench. Aerosols were generated from a buffer suspension containing φX174 viruses. Viral aerosols passed through the filter at an airflow rate of 85L/min. Particle counters and air samplers were placed upwind and downwind of the mask. Particles were counted and infectious viruses were quantified upwind and downwind to calculate the filtration efficiency for both particles and viruses. Each reusable mask was tested in triplicate for each washing cycle frequency (0x, 1x, 25x, 50x, 75x, and 100x).
Results and Discussion
Washing exerted a significant influence on filtration efficiency, with efficiency loss observed even after a single wash, further declining with additional washing cycles. Following a hundred washing cycles, the eAir mask exhibit the least resilience, experiencing a 25% reduction in efficiency against viruses. Conversely, the eMed 3 mask demonstrated the highest resistance, with only a 7% efficiency loss. Notably, a decries in filtration efficiency for particles smaller than 1 µm was also observed. Further investigations could explore the impact of alternative washing methods on the filtration efficiency of reusable masks.
Acknowledgment
Thanks to Frëtt Solutions for the masks