Table 3.

Scenarios of mitigation measures. VR is ventilation rate with outside air, or by high-volume HEPA filtering (last column).

Scenario	VR 0.35 hr−1	VR 2 hr−1	Masks, 70% Efficiency	Masks, 95% Efficiency	High-Vol VR 9 hr−1
A. Standard (passive ventilation)	+
B. Active ventilation		+
C. Active ventilation + medium efficient masks		+	+
D. Active ventilation + highly efficient masks		+		+
E. High-volume air filtration with HEPA					+