COVID-19: mask efficacy is dependent on both fabric and fit

Future Microbiol. 2021 Jan;16:5-11. doi: 10.2217/fmb-2020-0292. Epub 2020 Dec 22.


Aim: Face masks are an important addition to our arsenal in the fight against COVID-19. The aim of this study is to present a novel method of measuring mask performance which can simultaneously assess both fabric penetration and leakage due to poor fit. Materials & methods: A synthetic aerosol is introduced into the lung of a medical dummy. A conical laser sheet surrounds the face of the dummy where it illuminates the aerosol emitted during a simulated breath. The system is demonstrated with five mask types. Conclusions: The curved laser sheet highlights both penetration through the mask fabric and leakage around the edges of the mask. A large variation in both material penetration and leakage was observed.

Keywords: COVID-19; SARS-CoV-2; aerosols; coronaviruses; droplets; face coverings; masks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerosols / analysis
  • COVID-19 / prevention & control*
  • COVID-19 / virology
  • Clothing
  • Equipment Design
  • Humans
  • Masks / standards*
  • Materials Testing
  • Particle Size
  • Personal Protective Equipment / standards
  • SARS-CoV-2 / isolation & purification
  • Sodium Chloride
  • Textiles*


  • Aerosols
  • Sodium Chloride