Sodium 4-(4-(2-hydroxynaphthalenylazo)phenylazo)benzenesulphonate

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:

Mutagenic activity of some textile dyes in different test systems

Author:

Barbara Przybojewska, Boguslaw Barariski, Ewa Spiechowicz and Krystyna Sitarek

Year:

1988

Bibliographic source:

Toxicology letters, 40 (1988) 183-192

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Salmonella/microsome mammalian assay was performed to determine the mutagenic nature of Direct Red 81

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Direct Red 81

Cas Number:

2610-11-9

Molecular formula:

C29H19N5O8S2.2Na

IUPAC Name:

Direct Red 81

Details on test material:

- Name of test material: Direct Red 81
- IUPAC name: Direct Red 81
- Molecular formula: C29H19N5O8S2.2Na
- Molecular weight: 675.6081 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): 8.14% Cl

Specific details on test material used for the study:

- Name of test material: Direct Red 81
- IUPAC name: Direct Red 81
- Molecular formula: C29H19N5O8S2.2Na
- Molecular weight: 675.6081 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): 8.14% Cl

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Details on mammalian cell type (if applicable):

No data

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix was prepared from liver homogenate of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

0, 10, 100, 500 or 1000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Aqua distilled
- Justification for choice of solvent/vehicle: The test chemical was soluble in Aqua distilled

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Aqua distilled

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: TA1538, TA98, +S9 - 2-Aminofluorene -S9 - 4-Nitro-o-phcnylenediamine / TA100, +S9 - 2-Aminofluorene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: No data
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- 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: Duplicate

NUMBER OF CELLS EVALUATED: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: Yes, cell growth was noted

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:

An investigated compound was judged to have induced a positive response when a dose-related increase in the number of revertants was observed and the number of revertants exceeded the negative control values by at least 2-foId in at least two successive concentrations of the test chemical.

Statistics:

Mean ± SD

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Toxicity was noted at 1000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: No data
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: The highest doses of the dyes in the Salmonella/microsome test were chosen after preliminary solubility study.

COMPARISON WITH HISTORICAL CONTROL DATA: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data

Remarks on result:

other: No mutagenic potential

Any other information on results incl. tables

Table: Mutagenic response of Salmonella typhimurium mutants to Direct Red 81

Dose (µg/plate)	TA1537		TA100		TA1537		TA1538		TA98
	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
0	16 ± 7	12 ± 4	133 ± 14	118 ± 6	9 ± 3	12 ± 4	18 ± 4	27± 2	28 ± 5	39 ± 5
10	16 ± 3	13 ± 3	134 ± 13	129 ± 7	8 ± 2	10 ± 3	18 ± 3	24 ± 4	26 ± 4	32 ± 6
100	19 ± 8	10 ± 2	127 ± 19	145 ± 33	12 ± 7	10 ± 2	17 ± 3	28 ± 1	26 ± 1	30 ± 3
500	20±3	16 ± 2	148 ± 30	136 ± 25	9 ± 2	7 ± 1	19 ± 7	28 ± 4	20 ± 2	35 ± 2
1000	13 ± 5	9 ± 5	123 ± 12	128 ± 9	8 ± 4	10 ± 1	15 ± 5	22 ± 4	29 ± 5	33 ± 5

 

Table: Positive mutagen data

Strain	S9 mix	Compounds	Dose level (µg/plate)	His+ colonies/plate	No. of spontaneous revertants/plate
TA1535	-	Sodium azide	1.5	1080±172	19±5
TA1537	-	9-Aminoacridine	10	144±9	8±1
TA1538	-	4-Nitro-o-phenylenediamine	10	1374±82	16±4
	+	2-Aminofluorene	10	> 2000	21±7
TA98	-	4-Nitro-o-phenylenediamine	10	1014±118	21±1
	+	2-Aminofluorene	10	> 2000	23±4
TA100	-	Sodium azide	1.5	1452±165	119±16
	+	2-aminofluorene	10	> 2000	131±17

Applicant's summary and conclusion

Conclusions:

Direct Red 81 did not induce gene mutation in Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 in the presence and absence of S9 metabolic activation system and hence it is not likely to classify as a gene mutant.

Executive summary:

Salmonella/microsome mammalian assay was performed to determine the mutagenic nature of Direct Red 81. The study was performed using Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 in the presence and absence of S9 metabolic activation system. The test chemical was dissolved in Aqua distilled and used at dose levels of 0, 10, 100, 500 or 1000µg/plate. The doses for the main study were decided on the basis of preliminary dose range finding study. The plates were incubated for 48 hrs at 37˚C. An investigated compound was judged to have induced a positive response when a dose-related increase in the number of revertants was observed and the number of revertants exceeded the negative control values by at least 2-foId in at least two successive concentrations of the test chemical. Direct Red 81 did not induce gene mutation in Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 in the presence and absence of S9 metabolic activation system and hence it is not likely to classify as a gene mutant.