Biphenyl-4-yl-(9,9-dimethyl-9H-fluoren-2-yl)-[2-(9,9-diphenyl-9H-fluoren-4-yl)-phenyl]-amine

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test item was not mutagenic in the baterial reverse mutation assay according to OECD TG 471 with and without S9 mix.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 April 2017 - 13 April 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Version / remarks:

1993

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix from rats pretreated with ß-Naphthoflavone/Phenobarbital

Test concentrations with justification for top dose:

The test material showed very limited solubility in the vehicle. A maximum concentration of 88.9 μg/plate was selected, in order that initial treatments were performed up to the maximum recommended concentration according to current regulatory guidelines (OECD TG 471, 1997).

Vehicle / solvent:

- Vehicle/solvent used: acetone
- Justification for choice of solvent/vehicle: Comparing the standard solvents for this assay indicated the test item showed best solubility performance in acetone.

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

acetone

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

sodium azide

other: denauomycin, 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION:in agar (plate incorporation)

DURATION
- Exposure duration: 2-3 days

NUMBER OF REPLICATIONS: 3

Evaluation criteria:

A test material was to be defined as negative or non-mutagenic in this assay if
• the assay was to be considered valid, and
• "no" or "weak increases" occurred in the test series performed ("weak increases" randomly occur due to experimental variation)

For valid data, the test material was considered tobe positive or mutagenic if:
• a dose dependent (over at least two test material concentrations) increase in the number of revertants was induced, the maximal effect was a "clear increase", and the effects were reproduced at similar concentration levels in the same test system, or
• "clear increases" occurred at least at one test material concentration, higher concentrations showed strong precipitation or cytotoxicity, and the effects were reproduced at the same concentration level in the same test system.

In general, two series of experiments must be performed. However, there is no requirement for verification of aclearpositive response (OECD TG471, 1997).
Results which only partially satisfied the above criteria were dealt with on a case-by-case basis. Biological relevance was taken into account, for example consistency of response within and between concentrations and (where applicable) between experiments.

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Yes, at the highest concentration tested.

RANGE-FINDING/SCREENING STUDIES: Comparing the standard solvents for this assay indicated that the test item showed best solubility performance in acetone. Based on these prelirninary data, acetone was selected as vehicle for the current experiment. However, the test material showed very limited solubility in acetone also. A maximum concentration of 88.9 μg/plate was selected, in order that initial treatments were performed up to the maximum recommended concentration according to current regulatory guidelines (OECD TG471, 1997).

Conclusions:

The test item was not mutagenic in the baterial reverse mutation assay according to OECD TG 471 with and without S9 mix.

Executive summary:

The present study was conducted to investigate the test material for its mutagenic potential in a bacterial reverse gene mutation assay in the absence and in the presence of a rat liver metabolizing system (S9 mix).

The investigations for the mutagenic potential of the test item were performed using Salmonella typhimurium test strains TA 98, TA 100, TA 1535 and TA 1537, and Escherichia coli WP2 uvrA. The plate incorporation test with and without addition of liver S9 mix from rats pretreated with ß-Naphthoflavone/Phenobarbital was used. In this study, two experimental series were performed. The S9 mix used contained 10% S9 in the first and 20% S9 in the second series, respectively.

Solvent and positive control treatments were included for all strains. The mean numbers of revertant colonies all fell within acceptable ranges for solvent control treatments, and were clearly elevated by positive control treatments, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.

Following treatment of all bacteria test strains with the test item in the absence and presence of S9 mix, no relevant increases in revertant numbers were observed.

It was concluded that with and without addition of S9 mix as the exogenous metabolizing system, the test item was not mutagenic under the experimental conditions described.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The present study was conducted to investigate the test material for its mutagenic potential in a bacterial reverse gene mutation assay in the absence and in the presence of a rat liver metabolizing system (S9 mix).

The investigations for the mutagenic potential of the test item were performed using Salmonella typhimurium test strains TA 98, TA 100, TA 1535 and TA 1537, and Escherichia coli WP2 uvrA. The plate incorporation test with and without addition of liver S9 mix from rats pretreated with ß-Naphthoflavone/Phenobarbital was used. In this study, two experimental series were performed. The S9 mix used contained 10% S9 in the first and 20% S9 in the second series, respectively.

Solvent and positive control treatments were included for all strains. The mean numbers of revertant colonies all fell within acceptable ranges for solvent control treatments, and were clearly elevated by positive control treatments, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.

Following treatment of all bacteria test strains with the test item in the absence and presence of S9 mix, no relevant increases in revertant numbers were observed.

It was concluded that with and without addition of S9 mix as the exogenous metabolizing system, the test item was not mutagenic under the experimental conditions described.

Justification for classification or non-classification

Based on the available data, the test item is not considered to be classified and labelled as mutagenic according to Regulation (EC) No 1272/2008.