TY - JOUR
T1 - Evaluation of decontamination methods for commercial and alternative respirator and mask materials – view from filtration aspect
AU - Ou, Qisheng
AU - Pei, Chenxing
AU - Chan Kim, Seong
AU - Abell, Elizabeth
AU - Pui, David Y.H.
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/12
Y1 - 2020/12
N2 - This study aims to evaluate the filtration performance of three commercially available (3M 8210 respirator, Halyard 48207 surgical mask, and 3M 1820 procedure mask) and two alternative face mask and respirator materials (Halyard H600 sterilization wrap and Cummins EX101) after selected decontamination treatments, including isopropanol (IPA) treatments (soaking or spraying), ultraviolet germicidal irradiation (UVGI), and heat treatments (dry heat at 77 °C or steam heat). Both IPA soaking and spraying removed most electrostatic charges on all four electret materials (three commercial and one alternative), causing significant deterioration of filtration efficiency to unacceptable level. The other non-electret alternative material sustained its N95-grade performance after both IPA soaking and spraying treatments, demonstrating the possible application of IPA disinfection for non-electret alternative respirator/mask materials. UVGI preserved the filtration of all three commercially available respirator/mask materials after up to 10 treatments, suggesting it can be a possible decontamination method for hospital and clinic use without compromising respirator/mask performance. The considerations of the practical implementation of this method was discussed. Between the two heat treatment methods tested, dry heat showed better compatibility with electret material by sustaining both filtration efficiency and fit (tested on commercial respirator only), although adding moisture was reported in favor of virus inactivation. Heat treatment is easily accessible method for general publics to implement at home, while it is recommended to maintain the moisture level below saturation. Comparing to size-integrated method, the size-resolved fractional efficiency measurement technique, although more time consuming, proved to be a better method for evaluating respirator/mask filtration performance after decontaminations by providing more sensitive detection of performance degradation and the capability of distinguishing charge loss to other mechanisms causing efficiency deterioration. Detailed descriptions are provided in methodology part to emphasize the cares needed for an appropriate efficiency evaluation. The limited results in this study on worn masks made of alternative sterilization wrap indicated possible performance degradation of electret material caused by normal human wearing activities, suggesting the need of assessing respirator/mask decontamination strategy by testing practically worn-and-decontaminated/reused samples instead of unworn only-decontaminated counterparts.
AB - This study aims to evaluate the filtration performance of three commercially available (3M 8210 respirator, Halyard 48207 surgical mask, and 3M 1820 procedure mask) and two alternative face mask and respirator materials (Halyard H600 sterilization wrap and Cummins EX101) after selected decontamination treatments, including isopropanol (IPA) treatments (soaking or spraying), ultraviolet germicidal irradiation (UVGI), and heat treatments (dry heat at 77 °C or steam heat). Both IPA soaking and spraying removed most electrostatic charges on all four electret materials (three commercial and one alternative), causing significant deterioration of filtration efficiency to unacceptable level. The other non-electret alternative material sustained its N95-grade performance after both IPA soaking and spraying treatments, demonstrating the possible application of IPA disinfection for non-electret alternative respirator/mask materials. UVGI preserved the filtration of all three commercially available respirator/mask materials after up to 10 treatments, suggesting it can be a possible decontamination method for hospital and clinic use without compromising respirator/mask performance. The considerations of the practical implementation of this method was discussed. Between the two heat treatment methods tested, dry heat showed better compatibility with electret material by sustaining both filtration efficiency and fit (tested on commercial respirator only), although adding moisture was reported in favor of virus inactivation. Heat treatment is easily accessible method for general publics to implement at home, while it is recommended to maintain the moisture level below saturation. Comparing to size-integrated method, the size-resolved fractional efficiency measurement technique, although more time consuming, proved to be a better method for evaluating respirator/mask filtration performance after decontaminations by providing more sensitive detection of performance degradation and the capability of distinguishing charge loss to other mechanisms causing efficiency deterioration. Detailed descriptions are provided in methodology part to emphasize the cares needed for an appropriate efficiency evaluation. The limited results in this study on worn masks made of alternative sterilization wrap indicated possible performance degradation of electret material caused by normal human wearing activities, suggesting the need of assessing respirator/mask decontamination strategy by testing practically worn-and-decontaminated/reused samples instead of unworn only-decontaminated counterparts.
KW - Dry heat treatment
KW - Electret and non-electret media
KW - Fractional efficiency
KW - Steam heat treatment
KW - Ultraviolet germicidal irradiation
KW - Worn masks
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U2 - 10.1016/j.jaerosci.2020.105609
DO - 10.1016/j.jaerosci.2020.105609
M3 - Article
C2 - 32834104
AN - SCOPUS:85086856826
SN - 0021-8502
VL - 150
JO - Journal of Aerosol Science
JF - Journal of Aerosol Science
M1 - 105609
ER -