Dihydrogen [2,4-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)][3-hydroxy-4-[(2-hydroxy-1-naphthyl)azo]-7-nitronaphthalene-1-sulphonato(3-)]chromate(2-)

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Mutagenicity of azo-compounds — Improved method for detecting their mutagenicities by the Salmonella mutation test

Author:

T. Matsushima, B. Teichmann, M. Sawamura, T. Sugimura

Year:

1978

Bibliographic source:

Mutation research; 54 (2). 1978 220-221

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

Gene mutation toxicity study was performed to determine the mutagenic nature of Eriochrome Black T

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

(4Z)-4-[(1-hydroxynaphthalen-2-yl)hydrazinylidene]-7-nitro-3-oxonaphthalene-1-sulfonic acid

Cas Number:

1787-61-7

Molecular formula:

C20H13N3O7S.Na

IUPAC Name:

(4Z)-4-[(1-hydroxynaphthalen-2-yl)hydrazinylidene]-7-nitro-3-oxonaphthalene-1-sulfonic acid

Details on test material:

- Name of test material: Eriochrome Black T
- IUPAC name: (4Z)-4-[(1-hydroxynaphthalen-2-yl)hydrazinylidene]-7-nitro-3-oxonaphthalene-1-sulfonic acid
- Molecular formula: C20H12N3O7SNa
- Molecular weight: 461.385 g/mol

Specific details on test material used for the study:

- Name of test material: Eriochrome Black T
- IUPAC name: (4Z)-4-[(1-hydroxynaphthalen-2-yl)hydrazinylidene]-7-nitro-3-oxonaphthalene-1-sulfonic acid
- Molecular formula: C20H12N3O7SNa
- Molecular weight: 461.385 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): No data

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA98 and TA100

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

S9 metabolic activation system

Test concentrations with justification for top dose:

No data

Vehicle / solvent:

No data

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

not specified

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: Preincubation

DURATION
- Preincubation period: No data
- Exposure duration: No data
- Expression time (cells in growth medium): No data
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data
SPINDLE INHIBITOR (cytogenetic assays): No data
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: No data

NUMBER OF CELLS EVALUATED: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Other: No data

OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

The plates were observed for no. of revertants/plate

Statistics:

No data

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium, other: TA100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 2

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

No data

Remarks on result:

other: No mutagenic potential

Applicant's summary and conclusion

Conclusions:

Eriochrome Black T did not induce mutation in Salmonella typhimurium strains TA100, TA98, in the presence of S9 metabolic activation system. It however induced gene mutation in in strain TA98 in the absence of S9 metabolic activation system

Executive summary:

Gene mutation toxicity study was performed to determine the mutagenic nature of Eriochrome Black T. The mutagenicities of this benzidine diazo-dye was not detected by the Salmonella standard plate method with a metabolic activation system (S-9 Mix) or even by the more sensitive modification (preincubation method) in which tester strain was incubated with the test chemical and S-9 Mix at 30°C for 30 min before plating on minimal glucose agar plates.

Addition of riboflavin to the S-9 Mix (1µmole/ml of S-9 Mix) was necessary for demonstration of the mutagenicities of azo- and diazo-compounds by the preincubation method. Riboflavin enhanced the azo-reductase activity in S-9 mix. Eriochrome Black T did notinduce mutation in Salmonellatyphimurium strains TA100, TA98, in the presence of S9 metabolic activation system. It however induced gene mutation in in strain TA98 in the absence of S9 metabolic activation system.