Benzoic acid, 4-hydroxy-, docosyl ester

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP- and Guideline Study with no or minor deficiencies.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

docosyl 4-hydroxybenzoate

EC Number:

920-338-0

Cas Number:

109236-76-2

Molecular formula:

C29 H50 O3

IUPAC Name:

docosyl 4-hydroxybenzoate

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

The test item concentrations to be applied in the main experiments were chosen according to the results of the pre-experiment (see page 21). 5000 ug/plate was selected as the maximum concentration. The concentration range covered two logarithmic decades. Two independent experiments were performed with the following concentrations:
Experiment I:
31.6, 100, 316, 1000, 2500 and 5000 ug/plate
Experiment II:
15.8, 50, 158, 500, 1580 and 5000 u.g/plate
As the results of the pre-experiment were in accordance with the criteria described above, these were reported as a part of the main experiment I.

Vehicle / solvent:

The test item was dissolved in EtOH, processed by ultrasound (37°C) and diluted prior to treatment. The solvent was compatible with the survival of the bacteria and the S9 activity.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other: 4-nitro-o-phenylene-diamine; 2-aminoanthracene

Evaluation criteria:

Evaluation of Cytotoxicity
Cytotoxicity can be detected by a clearing or rather diminution of the background lawn (indicated as "B" in the result tables) or a reduction in the number of revertants down to a mutation factor of approximately < 0.5 in relation to the solvent control.

Evaluation of Mutagenicity
The Mutation Factor is calculated by dividing the mean value of the revertant counts through the mean values of the solvent control (the exact and not the rounded values are used for calculation).
A test item is considered as mutagenic if:
- a clear and dose-related increase in the number of revertants occurs and/or
a biologically relevant positive response for at least one of the dose groups occurs
in at least one tester strain with or without metabolic activation.
A biologically relevant increase is described as follows:
- if in tester strains TA 100 and TA 102 the number of reversions is at least twice as high
- if in tester strains TA 98, TA 1535 and TA 1537 the number of reversions is at least three times higher
than the reversion rate of the solvent control (5).
According to OECD guidelines, the biological relevance of the results is the criterion for the interpretation of results, a statistical evaluation of the results is not regarded as necessary.
A test item producing neither a dose related increase in the number of revertants nor a reproducible biologically relevant positive response at any of the dose groups is considered to be non-mutagenic in this system.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: Experiment I: toxic effects only in strain TA 102 at 5000 µg/plate (without metabolic activation). Experiment II: toxic effects only in tester strain TA 1535 at a dose of 5000 µg/plate (with metabolic activation).

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

In order to investigate the potential of 4-Hydroxybenzoic acid behenylester for its ability to induce gene mutations the plate incorporation test (experiment I and II) was performed with the Salmonella typhimarium strains TA 98, TA 100, TA 1535, TA 1537 and TA 102.

In two independent experiments several concentrations of the test item were used. Each assay was conducted with and without metabolic activation. The concentrations, including the controls, were tested in triplicate. The following concentrations of the test item were prepared and used in the experiments:

Experiment I:

31.6, 100,316, 1000, 2500 and 5000 µg/plate

Experiment II:

15.8, 50, 158, 500, 1580 and 5000 µg/plate

Precipitation of the test item was observed in all tester strains used in experiment I and II (with and without metabolic activation).

In experiment I toxic effects of the test item were observed only in tester strain TA 102 at a dose of 5000 µg/plate (without metabolic activation).

In experiment II toxic effects of the test item were noted only in tester strain TA 1535 at a dose of 5000 µg/plate (with metabolic activation).

No biologically relevant increases in revertant colony numbers of any of the five tester strains were observed following treatment with 4-Hydroxybenzoic acid behenylester at any concentration level, neither in the presence nor absence of metabolic activation in experiment I and II.

The reference mutagens induced a distinct increase of revertant colonies indicating the validity of the experiments.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, 4-Hydroxybenzoic acid behenylester did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.
Therefore, 4-Hydroxybenzoic acid behenylester is considered to be non-mutagenic in this bacterial reverse mutation assay.