Skip to main content

Advertisement

Table 1 Target and achieved aerosol concentrations and particles size of Graphistrength© C100. Temperature, relative humidity and oxygen concentration measured over the 90-day exposure period

From: Lung inflammation and lack of genotoxicity in the comet and micronucleus assays of industrial multiwalled carbon nanotubes Graphistrength© C100 after a 90-day nose-only inhalation exposure of rats

Groups Control Low Mid High
Target aerosol concentrations (mg/m3 air) 0 0.05 0.25 5.0
Achieved aerosol concentrations (mg/m3 air) - 0.06 ± 0.04 0.28 ± 0.06 4.84 ± 0.41
Mean mass median aerodynamic diameter (MMAD, μm) (gravimetric determination) - nda 1.62 ± 0.39 2.30 ± 0.34
    (n = 5) (n = 14)
Mean GSD (gravimetric determination) - nda 4.67 ± 4.81 2.47 ± 0.26
Mean percentage of particles < 3 μm (gravimetric determination) - nda 74.10 ± 14.00 63.49 ± 6.23
Count median aerodynamic diameter (CMAD, nm) (WPRS determination) - 196.2 ± 54.7 231,5 ± 65.1 208.0 ± 62.0
   (n = 14) (n = 14) (n = 14)
Mean temperature (°C) 23.2 ± 0.9 23.3 ± 0.7 23.6 ± 0.7 23.8 ± 0.6
Mean relative humidity (%) 5.8 ± 1.5 6.1 ± 1.7 6.1 ± 1.7 6.3 ± 1.6
Mean oxygen concentration (%) 20.8 ± 0.0 20.8 ± 0.0 20.8 ± 0.0 20.8 ± 0.0
  1. nd: not determined
  2. a at 0.05 mg/m3 due to the very low concentration, the particle size could not be determined by gravimetry at an air flow rate of 1 L/min. The aerosol concentrations at 0.05 and 0.25 mg/m3 were achieved by serial dilution with compressed, filtered, dry air of the 0.25 and 5.0 mg/m3 concentrations, respectively. Therefore, the MMAD and GSD at 0.05 mg/m3 are expected to be of the same order as at 0.25 mg/m3. This is also confirmed by particle size data from the 5-day study with sampling at an air flow rate of 9 L/min (see Additional file 1: Table S4 for details)