2-ethylhexyl diphenyl phosphate

Endpoint summary

Additional information

The key study for gene mutation in bacteria was a Bacterial Reverse Mutation Assay (Ames test), employing S. typhimurium TA1535, TA1537, TA1538, TA98 and TA100, and Saccharomyces cerevisiae D4. The concentrations used were 0.01, 0.1, 1.0, 5.0, and 10 ul/plate. The results of the tests conducted on 2EHDPP in the absence and in the presence of a metabolic activation system were all negative. 2EHDPP did not demonstrate genetic activity in any of the assays conducted in this evaluation and was considered not mutagenic under these test conditions.

The key study for gene mutation in mammalian cells was a Mammalian Cell Gene Mutation Test. Cells derived from the mouse lymphoma cell line L5178Y were grown in culture media containing 2EHDPP at concentrations of 0.002, 0.003, 0.006, 0.013 and 0.025 ul/ml (-S9 mix), and 0.006, 0.013, 0.025, 0.050, and 0.075 ul/ml (+S9 mix). 2EHDPP did not induce an increase in mutations at the TK locus in these cells at all concentrations tested with and without microsomal activation. As no evidence of mutagenic activity was obtained in this study, 2EHDPP was not mutagenic for mouse lymphoma L51784, TK+/- cells under the conditions of this evaluation.

The key study for cytogenicity was an in vivo Mammalian Bone Marrow Chromosome Aberration Test. The acute oral administration of 1500, 5000 and 15000 mg/kg bw of 2EHDPP to male and female rats produced no significant increases in the frequency of chromosomal aberrations when compared to the control group. Under the conditions of this in vivo cytogenetics study, 2EHDPP did not damage chromosomes in rat bone marrow cells even after exposure at dose levels producing toxicity. Therefore, 2EHDPP is considered not to be clastogenic at any of the levels tested.

Short description of key information:
In vitro
- Gene mutation in bacteria (Bacterial Reverse Mutation Assay/Ames) (similar to OECD 471): not mutagenic.
- In vitro Mammalian Cell Gene Mutation Test (similar to OECD 476): not mutagenic.

In vivo:
- In vivo Mammalian Bone Marrow Chromosome Aberration Test) (similar to OECD 475): negative.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

In all 3 key genetic toxicity studies (2 in vitro and 1 in vivo) 2EHDPP did not show any genotoxic potential. Therefore, it can be concluded that the substance is not mutagenic, and does not need to be classified for mutagenicity according to the criteria outlined in Annex I of 1272/2008/EC (CLP/EU-GHS) and Annex VI of 67/548/EEC.