Niobium hydride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / micronucleus study

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
The performance of the micronucleus study was not technically feasible due to the physical properties of the test material.
The test material was a silver grey solid, it was grounded with a mortar and pestle to obtain a powder before the solubility test was performed. The test material did not dissolve in the commonly used solvents dimethyl sulfoxide and ethanol nor could a homogeneous suspension be obtained at concentrations of 93.91, 50 and 5 mg/mL. All formulations were treated with ultrasonic waves for at least 43 minutes. At concentrations of 93.91 and 50 mg/mL a non-homogenous suspension was obtained with test material on the bottom of the test tube. At the concentration of 5 mg/mL a colourless solution with test material on the bottom was obtained. No homogeneous suspension or solution could be obtained with acetone, tetrahydrofuran, dimethylformamide and hexane at a concentration of 10 mg/mL. All formulations were treated with ultrasonic waves for at least 18 minutes. All formulations were again colourless solutions with test material on the bottom of the test tube.
Therefore it was concluded that due to the physical properties of the test material it was not possible to perform the in vitro micronucleus study.