TY - JOUR
T1 - Mask material filtration efficiency and mask fitting at the crossroads
T2 - Implications during pandemic times
AU - Ardon-Dryer, Karin
AU - Warzywoda, Juliusz
AU - Tekin, Rumeysa
AU - Biros, Jnev
AU - Almodovar, Sharilyn
AU - Weeks, Brandon L.
AU - Hope-Weeks, Louisa J.
AU - Sacco, Albert
N1 - Funding Information:
We gratefully acknowledge the Dean’s Council of the Edward E. Whitacre Jr. College of Engineering and other generous alumni supporting us in our help the people of West Texas.
Publisher Copyright:
©The Author(s).
PY - 2021
Y1 - 2021
N2 - The COVID-19 pandemic triggered the widespread use and need for respirators and face masks for the healthcare workers and public. In this study, several generally available respirators and mask designs were fit tested, and their materials were evaluated for filtration efficiency using 250 nm polystyrene latex particles. Efficiency testing was performed for 2 and 0.5 h at low (2.6 L min–1) and high (7.4 L min–1) airflows, respectively, using ~17.4 cm2 material area. As expected, all N95 and KN95 respirators passed the fit test, and their materials showed efficiencies > 95% for the entire experiment at both airflows. Of the three air filters used in the 3D-printed Montana masks, only the HEPA filter had a filtration efficiency > 95% at both airflows. Regardless of the insert material, the Montana mask failed all fit tests. Homemade duckbill masks made of Halyard H600 sterilization wrap and WypAll X80 reusable wipe also failed the fit test, and both filter materials had an average filtration efficiency < 95% at high airflows. To explain the filtration efficiency results, the structure and composition of all filter materials were determined using FE-SEM, and IR and Raman spectroscopy. In conclusion, when highly efficient materials are used in masks that do not fit the users properly, the potential of these materials to protect the users from aerosols is compromised. Therefore, the mask design is as important as the filtration efficiency of the mask material.
AB - The COVID-19 pandemic triggered the widespread use and need for respirators and face masks for the healthcare workers and public. In this study, several generally available respirators and mask designs were fit tested, and their materials were evaluated for filtration efficiency using 250 nm polystyrene latex particles. Efficiency testing was performed for 2 and 0.5 h at low (2.6 L min–1) and high (7.4 L min–1) airflows, respectively, using ~17.4 cm2 material area. As expected, all N95 and KN95 respirators passed the fit test, and their materials showed efficiencies > 95% for the entire experiment at both airflows. Of the three air filters used in the 3D-printed Montana masks, only the HEPA filter had a filtration efficiency > 95% at both airflows. Regardless of the insert material, the Montana mask failed all fit tests. Homemade duckbill masks made of Halyard H600 sterilization wrap and WypAll X80 reusable wipe also failed the fit test, and both filter materials had an average filtration efficiency < 95% at high airflows. To explain the filtration efficiency results, the structure and composition of all filter materials were determined using FE-SEM, and IR and Raman spectroscopy. In conclusion, when highly efficient materials are used in masks that do not fit the users properly, the potential of these materials to protect the users from aerosols is compromised. Therefore, the mask design is as important as the filtration efficiency of the mask material.
KW - Duckbill masks
KW - Face masks
KW - Filtration efficiency
KW - Respirators
UR - http://www.scopus.com/inward/record.url?scp=85109998943&partnerID=8YFLogxK
U2 - 10.4209/aaqr.200571
DO - 10.4209/aaqr.200571
M3 - Article
AN - SCOPUS:85109998943
VL - 21
JO - Aerosol and Air Quality Research
JF - Aerosol and Air Quality Research
SN - 1680-8584
IS - 7
M1 - 200571
ER -