Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

Triclosan was negative, with and without activation, in the in vitro tests in bacteria and mammalian cells. The in vitro chromosomal aberration assay in V79 cells showed increased incidences of cells with chromosomal damages. However, these findings were made at test concentrations that led to a ≥ 50% reduction of mitotic activity as early as 7 h post exposure. Therefore, the occurrence of chromosomal damage is unlikely to represent a primary genotoxic event. This appraisal is confirmed by two in-vitro UDS assays in primary rat hepatocytes that were negative even at much higher triclosan concentrations. In addition, an in-vivo micronucleus assay in mice was also without indication for a genotoxic potential of triclosan.

Although triclosan treatment did not suppress mitotic activity in bone marrow cells, the toxicokinetic studies clearly indicated that triclosan in blood reaches appreciable levels after oral administration. Since bone marrow is a well-perfused tissue, exposure of the bone marrow to the test material is ensured.


Short description of key information:
Several studies on the genotoxicity of triclosan under in vitro and in vivo test conditions are available.
In vitro genotoxicity studies retained as weight of evidence or key studies were the following:
- Ames Test according to OECD TG 471 (HRC ULR 215/88704): strain S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Ames Test according to OECD TG 471 (BASF 2014; 40M0435/10M214): strain E. coli WP2 uvr A
- Chromosome aberration assay according to OECD TG 473 (CCR 179100)
- Mouse Lymphoma TK Locus Assay similar to OECD TG 476 (HRC ULR 216/88644)
- UDS assay similar to OECD TG 482 (Pharmakon PH 311-CP-001-93)
In vitro genotoxicity studies retained for support were the following:
- UDS assay similar to OECD TG 482 8 IRI 4667)
- Mutagenicity Test on Saccharomyces Cerevisiae, no TG followed (Ciba-Geigy Ltd 78/3402)
In vivo genotoxicity study retained as key study was the following
- In vivo chromosome aberration assay according to OECD TG 475 (CCR 218305)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Owing to the results obtained from the different in vitro and in vivo genotoxicity tests, there is no need for classification of triclosan for mutagenicity according to the EU Directive 67/548/EEC, and there is no need for classification according to the Annex VI of the CLP regulation.