(phenylethyl)benzene

Endpoint summary

Additional information

Available information:

Mutagenicity in vitro in bacteria:

1,1 -DPE:

A distillate containing 75 % diphenyl ethane, was tested for mutagenicity in the Ames test according to OECD guideline 471 using 5 strains of Salmonella typhimurium (TA 1535, TA 1537, TA 1538, TA 98 and TA 100).

The test item produced no significant increase in revertants in any strain and was considered non-mutagenic in this test.

SAS-40:

SAS-40 was tested in the Salmonella typhimurium reverse mutation assay according to OECD/EC guidelines with five histidine-requiring strains of Salmonella typhimurium (TA1535, TA1537, TA1538, TA98 and TA100) with and without metabolic activation (S9 -mix). Based on the results of this study it can be concluded that SAS-40 is not mutagenic in the Salmonella typhimurium reverse mutation assay.

PTE:

Phenyl-tolyl-ethane was tested in the Salmonella typhimurium reverse mutation assay according to OECD/EC guidelines with four histidine-requiring strains of Salmonella typhimurium (TA1535, TA1537, TA98 and TA100) and in tester strain WP2uvrA with and without metabolic activation (S9 -mix). Phenyl-tolyl-ethane did not induce a significant dose-related increase in the number of revertant (His+) colonies in each of the four tester strains (TA1535, TA1537, TA98 and TA100) and in the number of revertant (Trp+) colonies in tester strain WP2uvrA both in the absence and presence of S9-metabolic activation.

In vitro chromosome aberration:

1,1 -DPE:

XZ 95510, a distillate containing 75% diphenylethane (DPE), was tested for clastogenic potential using Chinese hamster ovary (CHO) cells -in vitro according to OECD guideline 473 (In vitro Mammalian Chromosome Aberration Test). Cell cultures were exposed to XZ 95510 at concentrations of 5, 10, 20 and 40 ug/ml , both in the presence and absence of a metabolic activation system (Aroclor- 1254 induced rat liver S9-mix) . There was no reproducible evidence that XZ 95510 induced chromosome aberrations and there was no indication of chromosomal ploidy changes in either the presence or absence of the metabolic activation system.

PTE:

A study according to OECD guideline 473 was performed to assess the effect of Phenyl-tolyl-ethane on the number of chromosome aberrations in cultured peripheral human lymphocytes in the presence and absence of a metabolic activation system (phenobarbital and ß-naphthoflavone induced rat liver S9-mix). Phenyl-tolyl-ethane was not clastogenic in human lymphocytes under the experimental conditions described.

Mouse Lymphoma Assay:

PTE:

This study according to OECD guideline 476 was performed to investigate the potential of PTE to induce mutations at the mouse lymphoma thymidine kinase locus using the cell line L5178Y.

The test item did not induce mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the absence and presence of metabolic activation. Therefore, PTE is considered to be non-mutagenic under the conditions of the mouse lymphoma assay.

DNA Damage and Repair, Unscheduled DNA Synthesis in Mammalian Cells In Vitro

A sample of 99% diphenyl ethane was tested for genotoxicity by measuring unscheduled DNA synthesis (U.D. S.) in primary rat hepatocytes in -vitro according to OECD guideline 482 (Genetic Toxicology: DNA Damage and Repair, Unscheduled DNA Synthesis in Mammalian Cells In Vitro). None of the concentrations of 99% diphenyl ethane showed any evidence of increase DNA labelling. It was concluded that 99% diphenyl ethane showed no evidence of genotoxicity in this U. D. S. assay.

Genetic toxicity in vivo:

Micronucleus Assay:

SAS-40:

In a mouse micronucleus test following OECD-guideline 474 under GLP conditions, SAS-40 was administered intraperitoneally at the maximun tolerated dose (400 mg/kg bw).

SAS-40 did not significantly increase the number of micronucleated polychromatic erythrocytes or significantly decrease the ratio of polychromatic to normochromatic erythrocytes at any of the time points. It can be concluded that SAS-40 does not induce micronuclei.

Conclusion:

All in vitro and in vivo tests in genetic toxicity showed negative results. There is no reason to believe that the negative results would not be relevant to humans. No further testing is required.

Justification for selection of genetic toxicity endpoint
Conclusion based on the following assays: Bacterial reverse mutation assay (Ames test); Mammalian cell gene mutation assay; In vitro mammalian chromosome aberration test;DNA Damage and Repair (Unscheduled DNA Synthesis in Mammalian Cells In Vitro); in vivo micronucleus assay

Short description of key information:
Negative in all tests conducted (for details, see below).

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data, no classification is needed.