Reaction mass of Disodium dihydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]chromate(2-) and Sodium hydroxy[2-{[5-(hydroxy-kO)-3-methyl-1-(4-sulfophenyl)-1H-pyrazol-4-yl]diazenyl-kN1}benzoato(3-)-kO]chromate(1-)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

None

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only four tester strains tested; no tester strain to detect cross-linking mutagens was included

Principles of method if other than guideline:

None

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

[2-[[4,5-dihydro-3-methyl-5-oxo-1-(4-sulphophenyl)-1H-pyrazol-4-yl]azo]benzoato(3-)]chromium

EC Number:

276-702-8

EC Name:

[2-[[4,5-dihydro-3-methyl-5-oxo-1-(4-sulphophenyl)-1H-pyrazol-4-yl]azo]benzoato(3-)]chromium

Cas Number:

72496-90-3

Molecular formula:

C17H11CrN4O6S

IUPAC Name:

[2-[[4,5-dihydro-3-methyl-5-oxo-1-(4-sulphophenyl)-1H-pyrazol-4-yl]azo]benzoato(3-)]chromium

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

None

Method

Target gene:

None

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

S9-mix from rat liver

Test concentrations with justification for top dose:

33.3; 100.0; 333.3; 1000.0; 2500.0; and 5000.0 µg/plate

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Without metabolic activation - TA 1535 and TA 100

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

Without metabolic activation - TA 1537 and TA 98

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

With metabolic activaton - TA 1535, TA 1537, TA 98, TA 100

Details on test system and experimental conditions:

Without metabolic activation
TA 1535, TA 100, TA 102 - double distilled water
TA 15377 TA 98 - DMSO


With metabolic activation
TA 1535, TA 1537, TA 98, TA 100 - DMSO

Rationale for test conditions:

None

Evaluation criteria:

None

Statistics:

No appropriate statistical method is available.

Results and discussion

Test results

Key result

Species / strain:

other: 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

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

None

Remarks on result:

other: all strains/cell types tested

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:

FAT 20041/C was determined to be non-mutagenic in the bacterial reverse mutation assay.

Executive summary:

The study was performed to investigate the potential of FAT 20041/C to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100. The assay was performed in two independent experiments, both with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test article was tested at the following concentrations: 33.3; 100; 333.3; 1000; 2500; and 5000 µg/plate (active ingredient). Toxic effects, evidenced by a reduction in the number of revertants, occurred in strain TA 98 at 2500 and 5000 µg/plate without S9 mix in experiment I and in strain TA 1537 at 5000 µg/plate with metabolic activation in experiment II. The plates incubated with the test article showed normal background growth up to 5000 µg/plate with and without S9 mix in all strains used.

No substantial increases in revertant colony numbers of any of the four tester strains were observed following treatment with FAT 20041/C at any dose level, either in the presence or absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Appropriate reference mutagens were used as positive controls and showed a distinct increase of 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, FAT 20041/C is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.