Figure 4.

UVC irradiation for 240 s inactivates over 2.5 log reduction in EMCV viral titers. (A) Time course log reduction of EMCV PFU in N95 test coupons treated with UVC irradiation. N95 mask squares (2.5 cm²) with all layers were incubated with infection media spiked with EMCV for 15 min. The mask coupons were then placed on open 10 cm polystyrene cell culture dishes 15.2 cm from the lamp. After warming up the lamp, the coupons were treated for the indicated amount of time per each side, and were left in infection media at 4 °C overnight. One ml of the respirator derived media mix was used from each condition and was titered in VERO-CCL81 cells using standard plaque assays and crystal-violet staining. Each dot represents data from three independent experiments and plotted data bars represent mean and standard deviation for the triplicates. Vertical dashed line delineates untreated and treated parts of the experiment. Horizontal dotted line indicates the minimal level of detection (approximately 67 PFU ml⁻¹). Baseline for the assay is shown using a continuous line. (B) Regression analysis of viral reduction as per timely UVC irradiation.