Table 4.

Sampling times, air volumes, and recovery of Staphylococcus aureus colony-forming units (CFUs) from air samplers.

	Avg. sampling duration (min)	Avg. volume (L)	Standard deviation (L)	Range (L)	Coefficient of variation (%)	CFU/m³ range^a
Button sampler^a
Personal inhalable airborne	138	559	36	520–607	6%	<L OD - 9.10
Area inhalable airborne	103	431	97	330–571	22%	<L OD - 2.10
Impinger
	48	611	120	346–805	20%	<L OD - 8.60
Andersen impactor
And-5 min	5	153	17	140–170	11%	<L OD - 28.5
And - 10 min	10	293	16	275–312	6%	<L OD - 38.8
And-20 min	20	574	33	530–620	6%	<L OD - 61.3

Avg: average

<LOD: Below the limit of detection

Dissolution of gelatin filters was incomplete and eluate was further diluted; this may result in underestimation of CFU counts