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Updated: Dec 19, 2025

Absorption of Nasal and Bronchial Fluids: Precision Sampling of the Human Respiratory Mucosa and Laboratory Processing of Samples
Published on: January 21, 2018
A New Method for Testing Filtration Efficiency of Mask Materials Under Sneeze-like Pressure
L I Xiao1, Hiroshi Sakagami2, Nobuhiko Miwa3
1Department of Pharmacology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan xiaoli@tky.ndu.ac.jp.
Background:
Sneezes produce many pathogen-containing micro-droplets with high velocities of 4.5-50.0 m/s. Face masks are believed to protect people from infection by blocking those droplets. However, current filtration efficiency tests can't evaluate masks under sneeze-like pressure. The goal of this study was to establish a method to evaluate the filtration efficiency of mask materials under extreme conditions.
Materials And Methods:
Efficiency of surgical masks, gauze masks, gauze, cotton, silk, linen and tissue paper on blocking micro-droplet sized starch particles (average 8.2 μm) and latex microspheres (0.75 μm) with a velocity of 44.4 m/s created by centrifugation was qualitatively analyzed by using imaging-based analysis.
Results:
The 4 layers of silk could block 93.8% of microspheres and 88.9% of starch particles, followed by the gauze mask (78.5% of microspheres and 90.4% of starch particles) and the 2 layers of cotton (74.6% of microspheres and 87.5-89.0% of particles). Other materials also blocked 53.2-66.5% of microspheres and 76.4%-87.9% of particles except the 8 layers of gauze which only blocked 36.7% of particles. The filtration efficiency was improved by the increased layers of materials.
Conclusion:
Centrifugation-based filtration efficiency test not only compensates shortcomings of current tests for masks, but also offers a simple way to explore new mask materials during pandemics. Common mask materials can potentially provide protection against respiratory droplet transmission.

