Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

TGIC has been shown to cause gene mutations in-vitro in bacterial systems as well as in mammalian cell cultures systems.

It also caused chromosomal aberrations, micronuclei, and sister chromatid exchange in mammalian cell systems.

In-vivo, TGIC caused in a variety of rodent assays chromosomal aberrations , both in somatic as well as in germinal tissues.

However, no gene mutations have been detected in three dominant-lethal assays and in a mouse spot test. The reason for the lack of gene mutations in-vivo is not known, but it could have many reasons:

Either the systems used were not sensitive enough for gene mutations, or the major mutagenic activity of TGIC is to cause chromosomal aberrations, e.g. DNA breaks and not base modifications or base substitutions.

However, the observed effects are significant and make TGIC a cat II mutagen


Short description of key information:
TGICis mutagenic in-vitro and in-vivo.
It causes chromosomal effects in male germinal tissues such as testis and seminiferous tubules.
Primary and secondary spermatocytes are affected.
However, no gene mutations in the mammalian spot test and in the dominant-lethal test have been observed

Endpoint Conclusion: Adverse effect observed (positive)

Justification for classification or non-classification

Based on the in-vitro mutagenic effects and based on the in-vivo clastogenic effects in somatic as well as in germ cells the classification and labelling as Cat. 2 mutagen and R46 is justified.