Fig 1.
SARS-CoV-2 thermal stability on N95 respirator material.
SARS-CoV-2 was inoculated onto N95 respirators and were subsequently subjected to either 80°C of dry heat for 60 minutes or 100°C of dry heat for 30 minutes.
Table 1.
Description of OSHA guidelines on quantitative respirator fit testing procedures [17].
Fig 2.
Quantitative fit factors of N95 respirators.
Quantitative fit factors of N95 (a) 3M 1860, (b) 3M 1870, (c) Bacou Willson 801, and (d) BLS 120B respirators, treated with dry heat at 100°C for 30’ or 80°C for 60’ (n = 3), compared to untreated and autoclaved controls (n = 1).
Fig 3.
SEM characterizations of three layers in 3M 1860 N95 FFR.
(a-b) SEM/EDS images of cross section. (c-e) SEM images of top-down view of untreated 3M 1860 N95. (f-h) SEM images of top-down view of the of 3M 1860 N95 after dry heat treatment at 100°C for 4 cycles. (i-k) SEM images of top-down view of the of 3M 1860 N95 after autoclaving treatment.
Fig 4.
Raman spectra of three layers in 3M 1860 N95 FFR material.
Spectra before dry heat, after dry heat, and autoclave heat treatment for the respective layers.
Table 2.
Estimated filter efficiency derived from fit factors obtained from the PortaCount Pro 8048.