Table 2.

Summary of the estimated critical exposure times in hours at air exchange rates of 1, 5, 10, 15, and 20 h⁻¹ in rooms ranging from 20 to 300 m³ in size

Air exchange rate [h−1]	Space volume [m3]
	20	50	100	150	200	250	300
1	0.28	0.60	1.11	1.63	2.17	2.76	3.39
5	0.34	0.94	2.39	4.32	6.64	9.31	12.30
10	0.46	1.59	4.49	8.34	12.98	18.33	24.30
15	0.61	2.31	6.64	12.42	19.39	27.41	36.37
20	0.77	3.04	8.82	16.52	25.82	36.50	48.45