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Table 2 Dose groups, substances and dosing

From: The carcinogenic effect of various multi-walled carbon nanotubes (MWCNTs) after intraperitoneal injection in rats

Substance Carbon source Catalyst Generation method Length (μm) all fibers Length (μm) WHO fibers* Diameter (μm) WHO fibers* Specific fiber concentration (109WHO fibers*/mg) Fibers [length >20 μm] (% of WHO fibers*) Dose WHO fibers* 109per rat (targeted#) Dose WHO fibers 109per rat (actual##) Dose (mg in 2 ml)### Inner angle No. of rats
Medium control - - - - - - - - - - - - 50
MWCNT A low Benzene Fe Sublimation method 2.72 ± 2.29 8.57 ± 1.51 0.085 ± 1.60 2.39 3.81 1 0.48 0.2 174.85°±5.82° 50
MWCNT A high 5 2.39 1.0 50
MWCNT B low Cyclohexane Fe Aerosol method 2.13 ± 2.46 9.30 ± 1.63 0.062 ± 1.71 1.60 9.35 1 0.96 0.6 148.10°±11.48° 50
MWCNT B high 5 4.80 3.0 50
MWCNT C low Cyclohexane Fe Aerosol method 4.18 ± 2.41 10.24 ± 1.64 0.040 ± 1.57 10.91 11.77 1 0.87 0.08 144.55°±11.48° 50
MWCNT C high 5 4.36 0.4 50
MWCNT D low Acetonitrile Co Aerosol method 2.53 ± 2.02 7.91 ± 1.40 0.037 ± 1.45 30.15 2.13 1 1.51 0.05 Not measured 50
MWCNT D high 5 7.54 0.25 50
Long amosite asbestos - - - 6.22 ± 3.12 13.95 ± 2.10 0.394 ± 1.83 0.1 28.55 0.1 0.14 1.4 - 50
  1. Fiber types, lengths and diameters (geometric mean, GMSTD), % of WHO fibers* (length greater than 20 μm) and inner angles (to evaluate the degree of circumflexion of the different CNTs, the angle at the concave side [inner angle] was measured between two straight lines, the first from the beginning of the circumflexion to the middle and the second from the middle to the end of the circumflexion).
  2. *WHO fibers: length greater than 5 μm, diameter less than 3 μm, and a length-to-width ratio (aspect ratio) of at least 3:1.
  3. #Targeted fiber number dose according to WHO guideline and TRGS 905.
  4. ##Actual fiber number dose; deviations from target values are due to inhomogeneities during successive synthesis or suspension of test items.
  5. ###Total mass dose per rat in mg of substance including also fibers shorter than WHO fibers.