Hydrogen bis[2-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]benzoato(2-)]chromate(1-), compound with 2-ethylhexylamine (1:1)

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:

2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study according to current guideline and GLP regulations; Method does not apply Prival- modification

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

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:

Hydrogen bis[2-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]benzoato(2-)]chromate(1-), compound with 2-ethylhexylamine (1:1)

EC Number:

275-864-7

EC Name:

Hydrogen bis[2-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]benzoato(2-)]chromate(1-), compound with 2-ethylhexylamine (1:1)

Cas Number:

71701-15-0

Molecular formula:

C42H44CrN9O6

IUPAC Name:

Chromate(1-), bis[2-[2-[4,5-dihydro-3-methyl-5-(oxo-kO)-1-phenyl-1H-pyrazol-4-yl]diazenyl-kN1]benzoato(2-)-kO]-, hydrogen, compd. with 2-ethyl-1-hexanamine (1:1:1)

Method

Species / strain

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:

Rat liver S9 mix

Test concentrations with justification for top dose:

33; 1 00; 333; 1 000; 2500; and 5000 µg/plate

Vehicle / solvent:

DMSO (MERCK, D-64293 Darmstadt; purity> 99 %).

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other: 4-nitro-o-phenylene-diamine (4-NOPD); 2-aminoanthracene (2-AA)

Details on test system and experimental conditions:

METHOD OF APPLICATION:in agar (plate incorporation); preincubation;
DURATION
- Preincubation period: 60 minutes
- Exposure duration:48 h

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: other: back ground growth

Evaluation criteria:

Acceptability of the Assay
The Salmonella typhimurium and Escherichia coli reverse mutation assay is considered acceptable if it meets the following criteria:
regular background growth in the negative and solvent control
the spontaneous reversion rates in the negative and solvent control are in the range of our historical data
the positive control substances should produce a significant increase in mutant colony frequencies

Evaluation of Results
A test item is considered positive if a dose related increase in the number of revertants exceeding the threshold of twice or thrice the colony count of the corresponding solvent control is observed at more than one concentration. Furthermore, a biologically relevant and reproducible increase exceeding the threshold at one test concentration is considered as positive.
A test item producing neither a dose related increase in the number of revertants nor a biologically relevant positive response at any one of the test points is considered nonmutagenic in this system.
A biologically relevant response is described as follows:
An increase is considered relevant if the number of reversions is at least twice the spontaneous reversion rate in strains TA 98, TA 100, and WP2 uvrA or thrice in strains TA 1535 and TA 1537.
Also, a dose-dependent and reproducible increase in the number of revertants is regarded as an indication of possibly existing mutagenic potential of the test item regardless whether the highest dose induced the above described enhancement factors or not.

Statistics:

No statistical evaluation of the data is required.

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

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

During the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair
changes or frameshifts in the genome of the strains used.

Executive summary:

This study was performed to investigate the potential of the test item 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, and the Escherichia coli strain WP2 uvrA.

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 item was tested at the following concentrations: 33; 1 00; 333; 1 000; 2500; and 5000 µg/plate The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without metabolic activation in both independent experiments.

No relevant toxic effects, evident as a reduction in the number of revertants, occurred in the test groups with and without metabolic activation.

No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with

the test item

at any dose level, neither in the presence nor 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.

Conclusion

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

is considered to be non mutagenic in this Salmonella typhimurium and Escherichia coli reverse mutation assay.