Table 4.

Summary of the workplace related exposure studies

	Workplace	Type of activity	Nanomaterial	Metric	Results - remarks
[2]	Industrial production	Bagging areas of three plants	Carbon black	PSD(15-675 nm); MC; NC; CC	No significant release of nanoparticles detected, release of agglomerates (> 400 nm) of nanoparticles in all cases of bagging detected if open systems were used; Other sources also significantly influence nanoscale particle concentrations
[3]	Industrial production	Production and pelletizer areas of three plants	Carbon black	PSD(15-675 nm);MC;NC; CC	Significant release of nanoparticles (> 106 #/cm³) and their agglomerates detected in case of a leak in the pelletizing area; in case of good maintenance no significant release of NP from closed production and pelletizing processes; other sources significantly influenced particle number concentrations
[36]	Toner and printing inks industry	Bag emptying of powders	Fumed silica	NC (< 1 μm); PSD (< 1 μm); ASA (< 1 μm); morph.; CC	Significantly increased1 NC (> 100 nm) and ASA detected during bag emptying; confirmed by TEM analysis
[37]	Industrial manufacturing plant	Manual packaging, warehouse, pelletizing	carbon black	PSD (< 1 μm); LDSA (< 1 μm)	Higher NC and LDSA concentrations during activity than during non-activity
[41]	Industrial manufacturing facility	Liquid phase process, drying, grinding, handling,	Silver	PSD (15 nm-675 nm); morph	Significant release of particles < 100 nm as well as of agglomerates was observed during all processing steps as soon as the reactor, dryer and grinder were opened, leading to possible exposure even for wet production processes
[45]	Industrial production	Metalloxide production (gas burner) and embedding into a porous oxide matrix, bagging, handling, cleaning and maintenance	MeO (no further information)	NC (10-1000 nm) PSD (14-760 nm), MC PM1 (0.1-1000 nm).	Long term study on possible release of nanomaterial; Significant release of nanomaterial by 'open' production line, handling and cleaning < 1000 nm; Increased NC < 100 nm concurrent with production activity.
[46]	Small commercial nanotechnology production facility	Production of fullerenes (arc reaction), sweeping, vacuum cleaning	Fullerenes	PSD (14 nm - 673 nm), PM2.5 MC, PAH MC	Slightly elevated NC in work area compared to background at one day out of 4 possibly related to cleaning of fume hood; Very good containment of the nanomaterial in the fume hood (production and handling area)
[47]	Industrial production	Wet mill	Lithium titanate metal oxides	NC (10-1000 nm), PSD (300 nm - 10 μm)MC (respirable fraction), CC, morph.	Only large agglomerates have been detected
[48]	Industrial production	Bagging and agitation including use of vacuum cleaner during these work steps	Fullerenes	PDS (15 nm-10 μm), morph	Release of particles < 100 nm were observed during bagging and vacuum cleaning; also release of particles > 2 μm was observed during all work steps, including agitation.
[50]	Industrial production	Production and processing (bagging, handling CNF in dryer, thermal treatment, removal from dryer)	Carbon nanofibers	NC; MC respirable; ASA; photoelectric response; CO and CO2	Elevated NC and MC indicate release of significant amounts of nanoscale particles and their agglomerates; no definite indication on release of single and agglomerated carbon nanofibres.
[51]	Industrial production pilot plant, Industry processing	Production and maintenance (silicon), extrusion of CNT nanocomposites	Silicon; CNT	PSD (5-600 nm); NC; ASA	No changes in PSD and NC was observed during production, but spikes during cleaning of mostly agglomerated silicon (> 200 nm); High NC concentration observed in the extrusion area, but no specific CNT detection method was employed;
[56]	Industrial manufacturing	Production, filtration, bagging	TiO2, Al2O3	PSD (5-600 nm); MC PM1; CC, morph	Wet and combustion production processes were compared and no significant release of particles < 100 nm observed; in one case a bag was overfilled and release of agglomerates > 400 nm observed
[55,61]	Simulated industry workplace	Compounding of nanocomposites with nanoscale alumina	Al2O3	PSD (5.6-560 nm), morph.	Significant release, confirmed by STEM analysis
[4]	Laboratory and industrial production facility	Normal activities during batchwise production of SWCNT: collection, removal, cleaning, opening container, vacuum cleaning	SWCNT	NC (10-1000 nm), MC (size fraction not indicated), morph, CC	Likeliness of CNT exposure during production given; period of exposure relatively short (ca. 1 h) but concentration are sometimes high the exposure nearly pure nanomaterial.
[33]	Laboratory to industrial workplace	Synthesis of nanoobjects, handling and production of composite materials	CNT, CNF, Carbon Nanopearls, fullerenes, TiO2, Ag, Mn, Co-oxide, Fe-oxide, Al, SiFe, QDs	NC (15-1000 nm) for screening, PSD (300-1000 nm), MC, CC (not size selective)	Increased NC in all three investigated size classes (10-1000 nm, 300-500 nm, 500-1000 nm) indicate Release of nanomaterial during various of the investigated sites; no systematic analysis of the results is presented
[38]	Research Laboratory for use of carbon based ENMs	Transfer of CNMs; sonication in environmentally relevant matrices	Fullerenes, MWCNT; carbon black	PSD (300 - 10,000 nm); NC (10 - 1,000 nm)	Each activity resulted in increased particle number concentrations; TEM images clearly show CNM
[39]	Research laboratories	Scalable flame spray pyrolysis	NaCl, BiPO4, CaSO4, Bi2O3, TiO2, SiO2, WO3, Cu/ZN, Cu/SiO2, Cu/ZrO2, Ta2O5/SiO2, Pt/Ba/Al2O3	PSD (15-675 nm); NC (> 7 nm; > 10 nm), MC (< 1 μm; < 10 μm)	Concentration in near field and far field higher than in background in 40% of measured cases
[40]	Research laboratories	Plasma enhanced CVD; PVD; compounding of polymers with nanofillers	Nanofillers (not further specified)	PSD (5 nm - 20 μm); NC (< 370 nm)	Increased concentrations detected, but likely not caused by ENP release
[42]	Laboratory scale production	Machining/cutting	CNT hybrid composites	NC, PSD (5 nm - 20 μm), morph, PM10 MC	Small increases in NC during wet cutting, significant increases (ca. 300,000 #/cm³) during dry cutting; fibres detected in concentrations of 1-4 fibres/cm³ during dry cutting.
[43]	Various2	Mixing of powder and liquid; filling/emptying oven; suspension spraying; flame spraying	TnO, ZnO, InZnO, SiO2	PSD (14 nm-20 μm), NC (< 1 μm), MC (respirable and inhalable)	No evidence of release of ZnO and InZnO during handling; very high concentrations during spraying of silane and flame spraying of SiO2 suspension
[49]	Laboratory scale production	Production by chemical vapour deposition (CVD)	SWCNT, MWCNT	PSD (5 nm - 20 μm); morph	SWCNT and MWCNT release was determined in the production area in the fume hood, depending on process conditions; No significant amounts of CNT were detected in the breathing zone of a worker and the background.
[52]	Laboratory scale production and handling	Weighing, mixing with solvent, cutting	raw CNF and CNF composite	NC (10-1000 nm); PSD (10 nm - 10 μm); ASA; morph	Slight increases in NC for weighing, mixing of CNF and wet cutting. TEM picture reveal the release of CNF during these processes. Minor airborne CNF concentration during normal handling; Main increase in PSD for sizes < 400 nm.
[53]	Laboratory handling	Handling in fume hoods of nanomaterial powders, pouring, transferring	Al2O3, Silver	PSD (5-600 nm); morph	increased NC in the breathing zone of a worker mainly in size range > 100 nm but also partially < 100 nm during handling activity;
[54]	Laboratory scale production and handling	Growth, removal, shaving and transfer of CVD derived CNT	CNT	PSD (5-600 nm); NC (10-1000 nm); TP, ESP; MC	Neither TEM nor NC analysis reveal a release of CNT during these processes
[62]	Laboratory and industrial production	Four production facilities (2 × TiO2 by combustion, Ag by plasma and in liquid via citrate), collection of powders in fume hood and in liquid	TiO2, Silver	PSD (15-710 nm); MC; CC, morph	Lowest number concentration detection for in liquid production, higher particle number concentrations during combustion but also release from electro engines and other side activities