PIGMENT RED 5021B

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:

1991-06-26 until 1991-07-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, GLP compliance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 1983

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1984

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Details on test material:

- Purity: > 90%

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:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Rat-liver microsomal fraction S9, Aroclor 1254 indcued

Test concentrations with justification for top dose:

- With and without microsomal activation: 312.5-5000 µg/plate

Vehicle / solvent:

Dimethylsulfoxide (DMSO)

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

For strains TA 100, TA 1535 without metabolic activation system

Controls 2

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

For WP2uvrA without metabolic activation system

Controls 3

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

For TA 98 without metabolic activation system

Controls 4

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

For TA 1537 without metabolic activation system

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

For TA 100, WP2uvrA, TA 98, TA 1537 with metabolic activation system

Controls 6

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

For TA 1535 with metabolic activation system

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF EXPERIMENTS AND REPLICATIONS: two independent experiments, 3 plates per concentration

Evaluation criteria:

- Assay acceptance criteria: A test is considered acceptable if the mean colony counts of the control values of all strains are within the acceptable ranges and
if the results of the positive controls meet the criteria for a positive response. In either case the final decision is based on the scientific judgement of the Study Director
- Criteria for a positive response: The test substance is considered to be mutagenic in this test system if one or both of the following conditions are met:
1- At least a reproducible doubling of the mean number of revertants per plate above that of the negative control at any concentration for one or more of the following strains: S. typhimurium TA 98, TA 1535, TA 1537 and E. Coli WPuvrA
2- A reproducible increase of the mean number of revertants per plate for any concentration above that of the negative control by at least a factor of 1.5 for strain S. typhimurium TA 100
Generally a concentration-related effect should be demonstrable.

Statistics:

A statistical analysis was not performed.

Results and discussion

Test results

Test results 1

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:

cytotoxicity

Remarks:

only in strain TA 1537 at the highest concentrations; however, tested in all strains up to limit concentration

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Precipitation occurred in all tester strains at all dose levels.

RANGE-FINDING/SCREENING STUDIES: Six concentrations of the test item ranging from 20.6-5000 µg/plate were tested with strains S. typhimurium TA 100 and E.coli WP2uvrA to determine the highest concentration to be used in the mutagenicity assay. The experiments were performed with and without microsomal activation. From the results obtained, the highest concentration suitable for the mutagenicity test was selected to be 5000 µg/plate without activation and 5000 µg/plate with activation.

COMPARISON WITH HISTORICAL CONTROL DATA: Was in the historical control data range

ADDITIONAL INFORMATION ON CYTOTOXICITY: Owing to a growth-inhibiting effect of the test substance a reduction in the colony count occurred in the experiment without and with microsomal activation on strain TA 1537 at the upper concentrations.

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