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Toxicological information

Genetic toxicity: in vitro

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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:
From 11 JUN 2002 to 27 JUN 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study (OECD 471) with Prival modifications for azo-dyes

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not specified
Species / strain / cell type:
S. typhimurium TA 102
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9; hamster liver S9
Test concentrations with justification for top dose:
50, 160, 500, 1600, 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: solubility properties of the solvent
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide (TA 100, TA1535), 9-aminoacridine (TA 1537), 2-nitrofluorene (TA 98), mitomycin C (TA 102)
Remarks:
without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with metabolic activation (rat liver S9 mix)
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene (TA 100, TA 1535, TA 1537, TA 102), congo red (TA 98)
Remarks:
with metabolic activation (hamster liver S9 mix)
Details on test system and experimental conditions:
METHOD OF APPLICATION:
- plate incorporation assay with induced rat liver S9 mix (10% (v/v); induction with Aroclor 1254)
- preincubation assay with uninduced hamster liver S9 mix (30% (v/v))

DURATION
- Preincubation period: 20 to 30 minutes at 30 °C
- Exposure duration: at least 48 hours

NUMBER OF REPLICATIONS: 3 plates per strain and dose level, including controls

Evaluation criteria:
A test compound is classified as mutagenic if it has either of the following effects:
- 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 vehicle control at complete bacterial background lawn
- it induces a dose-related 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 to three concentrations of the test compound at complete bacterial background lawn
Statistics:
Arithmetic means and standard deviation of the counted colonies were calculated, as well as the respective dose/control ratio.

Results and discussion

Test resultsopen allclose all
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
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation:
visible precipitation of the test item:
- plate incorporation test: at 50 µg/plate and above
- preincubation test: with S9-mix at 500 µg/plate and above and without S9-mix at 160 µg/plate and above

COMPARISON WITH HISTORICAL CONTROL DATA: there were no deviations observed

Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

The test item showed no mutagenic activity in both experiments (plate incorporation assay, preincubation assay) each with and without metabolic activation.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

The test item did not exert mutagenic activity in the reverse bacterial mutation assay (plate incorporation assay and preincubation assay according to Prival) with and without metabolic activation.
Executive summary:

Mutagenic activity of the test item was investigated in Salmonella typhimurium strains TA 1535, TA 1537, TA98, TA100 and TA 102 with (induced rat liver S9 mix) and without metabolic activation at concentrations of 50, 160, 500, 1600, and 5000 µg/plate using the plate incorporation assay. Due to the test items characteristic as an azo-dye the test was also conducted using the Prival modification, i.e. testing the above mentioned bacterial strains in the preincubation assay with uninduced hamster liver S9 mix for metabolic activation. This test was performed using the concentrations 50, 160, 500, 1600, and 5000 µg/plate.

The test item did not reveal any mutagenic activity under the conditions tested. The appropriate reference mutagenes showed distinct positive mutagenic effects.