Field and Laboratory Measurements Related to Occupational and Consumer Exposures - Safety of Nanomaterials along Their Lifecycle - page 289

Evans et al. (2010) CNF PNC, SA, M Manufacturing and processes

CNF facility: production,
mixing, drying, thermal
treatment

Elevated PNC and MC indicate release of signiicant amounts (up to
1.15 × 10 6 #/cm 3 , not due to CNF) of nanoscale particles and their
agglomerates; no deinite indication of release of single and
agglomerated carbon nanoibers

Curwin and Bertke
(2011)

Metal oxides PSD, PNC, M,

SA

Exposure assessment survey at
seven facilities, small, medium,
and large manufacturers and
end users, only description of
task is handling or production

TiO 2 mass concentration varied from GM 10.56 (1.88) to 78.3 (5.6)
µg/m 3 , PNC varied from GM 7,214 (1.27)#/cm 3 to 28,991 (2.69)#/
cm 3 , SA from 32 µm 2 /cm 3 (2.4) to 145 µm 2 /cm 3 (7.98). Generally,
the greater mass of particles is found in the larger particle sizes.
However, for production processes, the predominant mass of
particles is found in the 0.1 to 1.0 μm particle diameter range

Dahm et al. (2012) CNT/CNF M (EC)

respirable

Six sites assessed, primary or
secondary manufacturers of
CNT/CNF, personal breathing
zone samples in occupational
setting

Dry powder handling, mass concentration respirable EC 0.25-8 µg/
m 3 (mean 4.5), production/harvesting 0.75-5.5 µg/m³ (mean 2.5).
During harvesting individual ibres were identiied

Dahm et al. (2013) CNT/CNF PNC, respirable

mass, SA

Six sites assessed, primary or
secondary manufacturers of
CNT/CNF, direct-reading
instrument in occupational
setting

Differences were not observed among the various sampled
processes compared with concurrent indoor or outdoor background
samples using different direct reading instruments (DRIs). These
data are inconsistent with results for ilter-based samples collected
concurrently at the same sites (Dahm et al. 2012). Signiicant
variability was seen between these processes as well as the indoor
and outdoor backgrounds. However, no clear pattern emerged
linking the DRI's results to the EC or the microscopy data (CNT
and CNF structure counts). With respect to PNC, on average
harvesting showed the highest concentrations, whereas, dry
powder handling (weighing, mixing, extrusion, transferring)
showed the highest mass concentration. Background
concentrations showed the highest SA concentration

( Continued )