3-hydroxy-N-(o-tolyl)-4-[(2,4,5-trichlorophenyl)azo]naphthalene-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:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test performed according to OECD test guideline and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

additionally modified version for azo-dyes

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Principles of method if other than guideline:

The assay was performed with and without rat liver and hamster liver microsomal activation.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

3-hydroxy-N-(o-tolyl)-4-[(2,4,5-trichlorophenyl)azo]naphthalene-2-carboxamide

EC Number:

229-440-3

EC Name:

3-hydroxy-N-(o-tolyl)-4-[(2,4,5-trichlorophenyl)azo]naphthalene-2-carboxamide

Cas Number:

6535-46-2

Molecular formula:

C24H16Cl3N3O2

IUPAC Name:

3-hydroxy-N-(2-methylphenyl)-4-[(2,4,5-trichlorophenyl)diazenyl]-2-naphthamide

Test material form:

solid: nanoform, no surface treatment

Details on test material:

Name of test material (as cited in study report): (no report title): Permanent-Rot FGR 02 (Pigment Red 112)
Analytical purity: Not specified

Method

Target gene:

TA 1537: hisC3076, rfa, uvrB
TA 98: hisD3052, rfa, uvrB +R
TA 1535: hisG46, rfa, uvrB
TA 100: hisG46, rfa, uvrB +R

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 (10%) and S9 mix from hamster liver (30%)

Test concentrations with justification for top dose:

Experiment I: 0, 4, 20, 100, 500, 2500 and 5000 µg/plate;
Experiment II and toxicity test: 0, 4, 20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: Without metabolica activation: sodium azide (TA100, TA1535), 9-aminoacridine (TA1537), 2-nitrofluorene (TA98); with rat liver S9-mix: 2-aminoanthracene (all strains); with hamster liver S9-mix: 2-aminoanthracene (TA100, TA1535, TA1537); congo red (TA98)

Details on test system and experimental conditions:

The assay was performed in two independent experiments:

experiment I: plate incorporation assay with and without induced rat liver S9 mix
experiment II: pre-incubation test with and without non-induced hamster liver S9 mix

Two independent experiments for each of the two protocols (incorporation and pre-incubation) were performed.

Hamster liver S9 mix, but not rat liver S9 mix, contained the reductive agent FMN.


DURATION
- Preincubation period: 30 min, 30°C
- Exposure duration: after solidification the plates were incubated for about 48 hours at 37°C in the dark

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY: existence of evaluable plates (> 0 colonies) at five concentrations or more

Evaluation criteria:

A test item is considered as a mutagen if
a) it produces at least a 2-fold increase in the mean number of
revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate control at complete bacterial lawn, or
b) it induces a dose dependent increase in the mean number of revertants per plate of at least
one of the tester strains over the mean number of revertants per plate of the appropriate vehicle
control in at least two or three concentrations of the test compound at complete bacterial background lawn.

Statistics:

not required

Results and discussion

Test results

Key result

Species / strain:

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

Remarks:

Visible precipitation of the test compound was observed at concentrations of 500 µg/plate and higher

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative with and without metabolic activation

Under the experimental conditions reported, including the Prival test method modification for azo compounds, the test item did not induce gene mutations by frameshifts or base-pair substitutions in the genome of the strains used. Therefore, the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Executive summary:

Under the experimental conditions reported, including the Prival test method modification for azo compounds,  the test item did not induce gene mutations by frameshifts or base-pair substitutions in the genome of the strains used. Therefore, the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.