Table 1.

Efficacy of 222-nm UVC light (0.1 mW/cm²) on reducing viable SARS-CoV-2

	UVC irradiation time
	Control	10 seconds	30 seconds	60 seconds	300 seconds
Mean viable SARS-CoV-2 (TICD50/mL) (SD)	2.05 ± 1.21 × 104	2.34 ± 0.86 × 103	6.32 ± 0.0 × 101	6.32 ± 0.0 × 101	6.32 ± 0.0 × 101
Log reduction		0.94	2.51	2.51	2.51
Mean SARS-CoV-2 RNA* (copies/test) (SD)	2.12 ± 0.27 × 107	5.75 ± 0.82 × 107	3.41 ± 1.08 × 107	2.95 ± 0.41 × 107	3.03 ± 1.73 × 107

SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; TCID₅₀, 50% tissue culture infectious dose; SD, standard deviation.

^⁎SARS-CoV-2 RNA was measured by quantitative reverse transcription PCR.