Direct Yellow 169

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP- and Guideline-conform study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): FAT 40'403/B: Direkt Gelb 169
- Physical state: solid
- Analytical purity: approx. 80 % active ingredient
- Lot/batch No.: SFO 0025 1211
- Expiration date of the lot/batch: January 28, 1994
- Stability under test conditions: Pure: stable for 2 years; In solvent: cf. RCC Project 282025
- Storage condition of test material: room temperature, light protected

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Species / strain 3

Species / strain / cell type:

E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

10.0; 100.0; 333.3; 1000.0; and 5000.0 microg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: solubility

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: sodium azide,4-nitro-o-phenylene-diamine,methyl methane sulfonate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: 10 hours at 37° C
- Exposure duration: 48 hours at 37° C

Evaluation criteria:

A test article is considered as positive if either a dose related increase in the number of revertants or, a significant and reproducible increase for at least one test concentration is induced. A test article producing neither a dose related increase in the number of revertants nor a significant and reproducible positive response at any one of the test points is considered non-mutagenic in this system.
A significant response is described as follows: A test article is considered as mutagenic if in the strains TA 100 and WP2 the number of reversions will be at least twice as high and in the strains TA 1535, TA 1537, TA 1538 and TA 9 8 it will be at least three times higher as compared to the spontaneous reversion rate.
Also, a dose-dependent increase in the number of revertants is regarded as an indication of possibly existing mutagenic potential of the test article regardless whether the highest dose induced the above described enhancement factors or not.

Statistics:

none

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

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:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

PRE-EXPERIMENT FOR TOXICITY
8 concentrations were tested for toxicity and mutation induction with each 3 plates. The plates with the test article showed normal background growth up to 5000.0 microg/plate in strain TA 98 and TA 100, respectively. According to the dose selection criteria, the test article was
tested at the following concentrations:
10.0; 100.0; 333.3; 1000.0; and 5000.0 microg/plate.

A slight toxic effect evidenced by a reduction in the revertant rate was observed in strain TA 1538 at 5000.0 ug/plate without S9 mix in experiment II. A seemingly toxicity was observed at 10.0, 333.3 and 1000.0 ug/plate in strain TA 1538 with S9 mix in experiment II. This effect is due to the relatively high value of the corresponding solvent control. Additionally, a toxic effect seemed to occur in strain TA 1537 where no revertants were found
on plate 2 at 1000.0 ug/plate with S9 mix in experiment II.
Therefore a third experiment was performed with the strains TA 1537 and TA 1538. In experiment III a slight toxic effect occurred at 5000.0
ug/plate without S9 mix in strain TA 1537. This effect is considered being irrelevant since it was due to the relatively high level of the corresponding solvent control. In this experiment no toxic effect occurred in strain TA 1537 without S9 mix as well as in strain TA 1538 with and without S9 mix.
The plates incubated with the test article showed normal background growth up to 5000.0 ug/plate with and without S9 mix in both experiments.
No substantial increases in revertant colony numbers of any of the six tester strains were observed following treatment with FAT 40'403/B at any dose level, neither in the presence nor in the absence of metabolic activation (S9 mix).
There was also no tendancy of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of significance.

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