Benzoic acid, 4-hydroxy-, 1,1'-(1,4-phenylene) 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

Study period:

1996-10-15 to 1997-01-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1983

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Hydrochinone-bis-p-hydroxybenzoate

IUPAC Name:

Hydrochinone-bis-p-hydroxybenzoate

Details on test material:

- Name of test material (as cited in study report): Hydrochinone-bis-p-hydroxybenzoate
- Physical state: solid
- Storage condition of test material: room temperature, light protected

Method

Target gene:

strain specific loci for the histidin gene

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Leberhomogenat (S9-Mix)

Test concentrations with justification for top dose:

Concentration range in the main test (with metabolic activation): 33.3, 100, 333, 1000, 2500 and 5000 µg/plate
Concentration range in the main test (without metabolic activation): 33.3, 100, 333, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

Solvent: DMSO (Dimethylsufoxid)

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- in agar (plate incorporation) and preincubation

DURATION
- Exposure duration: 48 h at 37 °C

NUMBER OF REPLICATES:
- Three replicates for each concentration/test compound

DETERMINATION OF CYTOTOXICITY
- Background lawn
- Reduction of spontaneous revertans

Evaluation criteria:

A test article ist considered positive if either a dose related and reproducible increase in the number of revertants or a biologically relevant and reproducible increase for at least one test concentration is induced.
A biological relevant response is described as follows:
A test article is considered mutagenic if the number of reversions is at least twice the spontaneous reversion rate in strains TA98 and TA 100 or thrice on TA 1535 and TA 1537
mutagenicity test was judged to be valid if the following conditions are met:
- Integrity of the tester strain for the respective genetic modifications
- Spontaneous revertants are in a given range
- Background lawn

Statistics:

For the three replicates the mean and standard deviation was calculated

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Remarks:

max. dose 5000 g/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
8 concentrations with TA98 an TA100

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Precipitation of the test article occured at concentrations of 2500 µg/plate and above

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

The tested substance did not induce back mutations at the respective histidine gene loci of the used tester strains (TA 98, TA 100, TA 1535, TA 1537) with and without metabolizing enzymes.

Executive summary:

The test article Hydroquinone-bis-p-hydroxybenzoate was assessed for its potential to induce gene mutations according to the plate incorporation and the preincubation test using Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537. The study followed the OECD Guideline 471 (1983). The assay was performed in two independent experiments both with and without liver microsomal activation. The concentrations covered the range from 33.3 to 5000 µg/plate. No relevant toxic effects occured in all experiments. No substantial increase in revertant colony numbers were observed in any experiment with the test substance. Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies.

In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test article did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore

Hydroquinone-bis-p-hydroxybenzoate is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.