. 2014 Feb 28;52(3):190–198. doi: 10.2486/indhealth.2013-0117

Table 2. Particle size in two silica nanoparticle manufacturing factories.

Product type	Particle size (nm)
	Bulk powder	Workplace air^†		Ambient air (GMD)
	Bulk powder	GMD^‡	Agglomerate	Ambient air (GMD)
FS	12	64	hundreds of nanometers to a few microns	50
SS	100	94	hundreds of nanometers to a few microns	47

FS: fumed silica nanoparticle, SS: sol-gel silica nanoparticle. ^† In working. ^‡ Geometric mean diameter from the scanning mobility particle sizer (SMPS). Bulk powder: physical diameter of primary particle obtained from TEM analysis. Agglomerate: physical diameter of airborne agglomerate obtained from TEM analysis.