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Additional information

Ames Test

Norbornene was tested in a reverse gene mutation assay (Ames test) in bacteria (S. typhimuriumTA98; TA 100; TA1535; TA1537) in concentrations ranging from 0 to 5000 µg/plate in the presence and absense of mammalian metabolic activation (S9 mix induced from rat liver). The study was performed according to OECD 471 under GLP.

there was no evidence of induced mutant colonies over background. Cytotoxicity was obsevered with TA 100 at the highest concentrations of 2500 and 5000 µg/plate.

Chromosomal Aberration

In a first study (W. Müller, 1995) norbornene was assessed for its mutagenic potential in vitro in the chromosomal aberrationtest with two independant experiments with and without metabolic activation. No relevant reproducible enhancement of metaphases with aberrations over the range f the solvent control was found at any of the used concentrations. Cyctotoxicity was observed above 100 µg/ml.

In a second supporting study (A.Czich, 1997) again no increased, biologically relevant frequency of cells with structural chromosomal aberrations or polyploid metaphases could be observed. Cytotoxicity set in at and above concentrations of 150 µg/ml.

HGPRT

2 -Norbornene was tested in the intro HGPRT gene mutation assay with the V79 Chinese hamster cell line with and without metabolic activation. The test was carried out at dose levels from 10 -150 µg/ml, at higher dose levels strong cytotoxicity had been observed.

no effects judged to be of biological relevance were observed, the substance did not induce gene mutations under the experimental conditions.


Short description of key information:
2-Norbornene did not induce genetoxic effects in in vitro studies including an Ames test, two chromosomal aberration tests and one HGPRT-test on V79 Chinese hamster cells

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

no indication of gene-toxicity in any of the tests.