N,N'-naphthalene-1,5-diylbis[4-[(2,3-dichlorophenyl)azo]-3-hydroxynaphthalene-2-carboxamide]

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: comparable to guideline study with acceptable restrictions (limited details of study protocol, only plate incorporation protocol [preincubation is recommended for azo-dyes], no GLP; purity not specified)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report Date:

1985

Materials and methods

Test guideline

Qualifier:

equivalent or similar to

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only plate incorporation protocol, limited documentation

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Analytical purity: commercial grade
- Lot/batch No.: Kores sample TS 884
- Stability under test conditions: ensured

Method

Species / strain

Species / strain / cell type:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 102 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

1 ml activation mixture contains: 0.3 ml S9 fraction of liver from rats induced with Aroclor 1254 and 0.7 ml of a solution of co-factors

Test concentrations with justification for top dose:

First experiment; preliminary toxicity test: 0.08 - 5000 µg/plate
Second experiment; main experiment: 20, 78, 313, 1250 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO (suspension)

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Without S9-mix: 5 and 10 µg DR for TA 98; 0.125 and 0.25 µg 4-NQO for TA 100; 0.5 and 1.0 µg MMC for TA 102; 2.5 and 5.0 µg SA for TA 1535; for 50 and 100 µg 9AA for TA 1537.

Remarks:

Positive control substances without S9-mix (continue): : 5 µg 2-AA for TA 98, TA 100 and TA 1537; 20 µg 2-AA for TA 102 and 250 µg CCP for TA 1535.

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation), in triplicates

DURATION
- Exposure duration: 48 hours at 37 °C

SELECTION AGENT (mutation assays): histidine deprivation

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:

Doubling of the colony number is given as a cut-off value in the report.

Statistics:

When the colonies had been counted, the arithmetic mean was calculated.

Results and discussion

Test results

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 102 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

no increase in the number of revertants in test groups in comparison with the negative control treatment was observed

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

a growth-inhibiting effect of the test substance was observed with strain TA 102 in the experiments without and with microsomal activation at the highest concentration.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: at the concentrations of 78µg/plate and above, the substance precipitated in soft agar.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Salmonella/mammalian-microsome mutagenicity test

Metabolic activation	Test substance concentration (µg/plate)	Number of revertants per plate (arithmetic mean)
		TA 98	TA 100	TA 102	TA 1535	TA 1537
Without S9-mix	Negative control (DMSO)	23	143	261	14	10
	20 µg/plate	30	138	270	16	10
	78 µg/plate	25	136	260	19	8
	313 µg/plate	22	128	244	14	6
	1250 µg/plate	25	132	288	13	8
	5000 µg/plate	30	125	192	12	5
	Corresponding positive control	450-758	563-1149	694-1090	746-869	31-646
With S9-mix	Negative control (DMSO)	50	142	232	9	15
	20 µg/plate	49	138	339	13	20
	78 µg/plate	48	140	364	9	15
	313 µg/plate	47	123	312	11	7
	1250 µg/plate	56	133	306	15	12
	5000 µg/plate	53	109	87	17	9
	Corresponding positive control	963	1266	1485	482	63

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative