Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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:
2000-10-11 to 2001-02-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Gruideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
S. typhimurim histidine reversion system
E. coli tryptophan reversion system
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A pKM 101
Metabolic activation:
with and without
Test concentrations with justification for top dose:
5, 15, 50, 150, 500, 1500 and 5000ug/plate
Vehicle / solvent:
water containing 0.15%agar
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
Migrated to IUCLID6: strains TA98, TA1537 and TA100 with S9
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
Migrated to IUCLID6: strain TA98 without S9
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
Migrated to IUCLID6: strain TA100 and TA1535 without S9
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene strains TA1535 and E.coli with S9
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
Migrated to IUCLID6: strain TA1537 without S9
Positive controls:
yes
Positive control substance:
other: AF-2 E.coli without S9
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation;
DURATION
- Preincubation period: 30 minutes
- Exposure duration: at least 48 h
NUMBER OF REPLICATIONS: 3
DETERMINATION OF CYTOTOXICITY
- Method: relative total growth;
Evaluation criteria:
The mutation factor is calculated by dividing the mean value of the revertant counts through the mean values of the extract vehicle control. A test item is considered as mutagenic if:
- a clear and dose-related increase in the number of revertants occurs and/or
- a biologically relevant positive response for at least one of the dose group occurs in at least one tester strain with or without metabolic activation.
A biologically relevant increase is described as follows:
- if in tester starin TA 100 and E. coli WP2 uvrA the number of reversions is at least twice as high
- if in tester starin TA 98 TA 1535 TA 1537 the number of reversions is at leastthree times higher as high than the reversion rate of the extract vehicle control

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:
E. coli WP2 uvr A pKM 101
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
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 (with and without metabolic activation)

It is concluded that, under the test conditions employed, Nb2O5 Niobium Pentoxide Grade LN showed no evidence of mutagenic activity in this bacterial system.