TY - JOUR
T1 - One year of surgical mask testing at the University of Bologna labs
T2 - Lessons learned from data analysis
AU - Boi, C.
AU - Borsetti, F.
AU - Brugo, T. M.
AU - Cappelletti, M.
AU - De Angelis, M. G.
AU - Fedi, S.
AU - Di Giacomo, S.
AU - Fabiani, T.
AU - Foli, G.
AU - Garelli, A.
AU - Genchi, U.
AU - Ghezzi, D.
AU - Gualandi, C.
AU - Lalli, E.
AU - Magnani, M.
AU - Maurizzi, A.
AU - Mazzi, F.
AU - Mehrabi, N.
AU - Minelli, M.
AU - Montalbano, R.
AU - Morelli, L.
AU - Nici, S.
AU - Onesti, R.
AU - Paglianti, A.
AU - Papchenko, K.
AU - Pappalardo, S.
AU - Parisi, N. F.
AU - Rapino, S.
AU - Reggio, M.
AU - Roselli, M.
AU - Ruggeri, E.
AU - Sabatini, L.
AU - Saracino, E.
AU - Scarponi, G. E.
AU - Serra, L.
AU - Signorini, V.
AU - Storione, A.
AU - Torsello, M.
AU - Tugnoli, E.
AU - Vargiu, C. M.
AU - Vidali, G.
AU - Violante, F. S.
N1 - Funding Information:
Safety Mask (Project n. PG/2020/341799) funded under the Emilia Romagna Regional Founding program, POR-FESR) and Open Mask Lab, https://site.unibo.it/open_mask_lab/en (EU Horizon Programme call H2020-INFRAEOSC-05-2018-2019 GA 831644) are gratefully acknowledged for the financial support. The research team wish to show the appreciation to Cavazza Anna sas (Bologna, Italy), and Giacomo Cesari in particular, IMA SpA (Ozzano Emilia (Bologna), Italy) and the Mechanical and Mining Engineering alumni association of the University of Bologna for their support on lab creation, generously donating tools and instruments. Prof. Vittorio Colombo and Dr. Romolo Laurita (Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Italy) for supplying the aerosol nebulizer on the first stage of the project. Dr. Paolo Mandrioli (Senior Scientist Associate at the Institute of Atmospheric Sciences and Climate (CNR-ISAC), Bologna, Italy) is acknowledged for advice and support for the attainment and use of the 6 stage Andersen impactor. The authors are grateful to MD Andrea Berlingeri and to Prof Tiziana Lazzarotto (Department of Experimental, Diagnostic and Specialty Medicine – DIMES) for providing materials and reagents during the initial experimental setting and the first stage of mask testing.
Funding Information:
Safety Mask (Project n. PG/2020/341799) funded under the Emilia Romagna Regional Founding program, POR-FESR) and Open Mask Lab, https://site.unibo.it/open_mask_lab/en (EU Horizon Programme call H2020-INFRAEOSC-05-2018-2019 GA 831644) are gratefully acknowledged for the financial support.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/8/1
Y1 - 2022/8/1
N2 - The outbreak of SARS-CoV-2 pandemic highlighted the worldwide lack of surgical masks and personal protective equipment, which represent the main defense available against respiratory diseases as COVID-19. At the time, masks shortage was dramatic in Italy, the first European country seriously hit by the pandemic: aiming to address the emergency and to support the Italian industrial reconversion to the production of surgical masks, a multidisciplinary team of the University of Bologna organized a laboratory to test surgical masks according to European regulations. The group, driven by the expertise of chemical engineers, microbiologists, and occupational physicians, set-up the test lines to perform all the functional tests required. The laboratory started its activity on late March 2020, and as of the end of December of the same year 435 surgical mask prototypes were tested, with only 42 masks compliant to the European standard. From the analysis of the materials used, as well as of the production methods, it was found that a compliant surgical mask is most likely composed of three layers, a central meltblown filtration layer and two external spunbond comfort layers. An increase in the material thickness (grammage), or in the number of layers, does not improve the filtration efficiency, but leads to poor breathability, indicating that filtration depends not only on pure size exclusion, but other mechanisms are taking place (driven by electrostatic charge). The study critically reviewed the European standard procedures, identifying the weak aspects; among the others, the control of aerosol droplet size during the bacterial filtration test results to be crucial, since it can change the classification of a mask when its performance lies near to the limiting values of 95 or 98%.
AB - The outbreak of SARS-CoV-2 pandemic highlighted the worldwide lack of surgical masks and personal protective equipment, which represent the main defense available against respiratory diseases as COVID-19. At the time, masks shortage was dramatic in Italy, the first European country seriously hit by the pandemic: aiming to address the emergency and to support the Italian industrial reconversion to the production of surgical masks, a multidisciplinary team of the University of Bologna organized a laboratory to test surgical masks according to European regulations. The group, driven by the expertise of chemical engineers, microbiologists, and occupational physicians, set-up the test lines to perform all the functional tests required. The laboratory started its activity on late March 2020, and as of the end of December of the same year 435 surgical mask prototypes were tested, with only 42 masks compliant to the European standard. From the analysis of the materials used, as well as of the production methods, it was found that a compliant surgical mask is most likely composed of three layers, a central meltblown filtration layer and two external spunbond comfort layers. An increase in the material thickness (grammage), or in the number of layers, does not improve the filtration efficiency, but leads to poor breathability, indicating that filtration depends not only on pure size exclusion, but other mechanisms are taking place (driven by electrostatic charge). The study critically reviewed the European standard procedures, identifying the weak aspects; among the others, the control of aerosol droplet size during the bacterial filtration test results to be crucial, since it can change the classification of a mask when its performance lies near to the limiting values of 95 or 98%.
KW - Bacterial filtration
KW - Breathability
KW - COVID-19
KW - Pandemic spread prevention
KW - Surgical masks
UR - http://www.scopus.com/inward/record.url?scp=85129811675&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2022.121180
DO - 10.1016/j.seppur.2022.121180
M3 - Article
C2 - 35573908
AN - SCOPUS:85129811675
VL - 294
JO - Separation and Purification Technology
JF - Separation and Purification Technology
SN - 1383-5866
M1 - 121180
ER -