Figure 2

Experimental design and controls for SARS-CoV-2 dose response measurement on N95 coupons. (A) Using the optical model and validating in situ, five locations within the decontamination chamber receiving similar UV-C doses (< 5% variation between mean in-situ dose measurements at each location) were identified. To inform biopsy location, the optical model also assessed the impact of each coupon seam (Figure S17; modeled as 15 mm wide × 2.5 mm tall × 1 mm thick absorbing rectangular volumes at the right-hand side of each coupon) on UV-C distribution. In-situ measurements were made using PCIs to simultaneously measure dose received at the PCI and 3 coupon locations while simultaneously recording irradiance with the radiometer. Mean and standard deviation are indicated for the in-situ measurements. (B) SARS-CoV-2 inactivation did not depend on the expiration status of 3M 1860 N95 coupons used in this study (N = 2 replicates/condition). (C) Comparison of SARS-CoV-2 survival on N95 coupons at room temperature and within the chamber shielded from UV-C during illumination demonstrates that chamber heating does not impact inactivation. p > 0.9999, Wilcoxon matched-pairs signed rank 2-tailed test. Bars denote mean of N = 3 measurements per condition; whiskers denote standard deviation; points denote individual measurements.