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Table 4 Summary of the workplace related exposure studies

From: Nanoparticle exposure at nanotechnology workplaces: A review

 

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