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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
other: read across from supporting substance
Adequacy of study:
key study
Study period:
From January, 11 to February, 07 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
not specified
Qualifier:
according to
Guideline:
EPA OTS 798.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
Range finding test: 20.58, 61.73, 185.19, 555.56, 1666.67, 5000.00 µg/plate mutagenicity tests: 61.7, 185.19, 555.56, 1666.67, 5000.0 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO, Bidistilled water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
other: 2-Aminoanthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium.
Inoculates from frozen master copies were set up monthly. They were grown in liquid nutrient broth medium (NB-medium) overnight and then plated on NB-agar. After incubation, single colonies were taken from the plates, grown overnight in liquid NB-medium and then used for the experiment.
Statistics:
A statistical analysis of the test data was not performed. The use of statistical methods concerning this particular test system is not generally recommended

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:
not determined
Vehicle controls validity:
not examined
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

Range finding test

Six concentrations of test item ranging from 20.6 to 5000.0 µg/plate were tested with strain Salmonella typhimurium TA 100 to determine the highest concentration to be used in the mutagenicity assay. The experiments were performed with and

without metabolic activation. Normal background growth was observed. The numbers of revenant colonies were not reduced. From the results obtained, the highest concentration suitable for the mutagenicity test was selected to be 5000.0 µg/plate with and without metabolic activation.

Mutagenicity test,

In the mutagenicity tests normal background growth was observed with all strains at all concentrations. The numbers of revertant colonies were not reduced. The test substance exerted no toxic effect on the growth of the bacteria.

Applicant's summary and conclusion

Conclusions:
The substance and its metabolites did not induce gene mutations in the strains of Salmonella typhimurium used.
Executive summary:

The substance has been tested for mutagenic effects in vitro in histidine-requiring strains of Salmonella typhimurium according to the OECD Guideline 471 and in compliance to the GLP Pinciples.

The following strains of Salmonella typhimurium were used: TA 98, TA 100, TA 102, TA 1535 and TA 1537. The test was performed with and without the addition of rat-liver post mitochondrial supernatant (S9 fraction) as an extrinsic metabolic activation system. The compound was tested as a suspension in DMSO at five concentrations in the range of 61.7 to 5000.0 µg/plate in the presence and absence of a metabolic activation system (rat-liver post mitochondrial supernatant: S9-fraction). In order to confirm the results, the experiments were repeated with and without metabolic activation at five concentrations in the same concentration range. Each strain was additionally tested in the presence and in the absence of a metabolic activation system with a suitable, known mutagen as positive control. In both experiments, performed with and without metabolic activation, none of the tested concentrations of test substance led to an increase in the incidence of histidine-prototrophic mutants by comparison with the negative control, therefore the substance is considered as not mutagenic