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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006
Reference Type:
publication
Title:
No information
Author:
Wirnitzer, U. et al.
Year:
2009
Bibliographic source:
Toxicology Letters 186, 160-165

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
GLP compliance:
yes (incl. certificate)
Remarks:
deviation: no analysis was performed on stability of the test item in the vehicle and no test was performed concerning the homogeneity of the test substance in formulation.
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced male rat liver S9 mix
Test concentrations with justification for top dose:
0, 50, 158, 500, 1581, 5000 µg/plate (without and with S9 mix)
Vehicle / solvent:
Solvents used: deionized water (test substance, mitomycin C), DMSO (sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, cumene hydroperoxide, 2-aminoanthracene)
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, mitomycin C, cumene hydroperoxide (only used without S9 mix) and 2-aminoanthracene (only used with S9 mix)
Details on test system and experimental conditions:
METHOD OF FORMULATION: Test substance was suspended in deionized water by using sonocation for total time of 30 minutes. To avoid heating the water of the ultrasonic bath to more than 25°C ice was added for at least 15 minutes. A black dispersion was formed which was well applicable with pipettes. The suspension was mixed prior to administration.
Evaluation criteria:
A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537, at least a threefold increase should be reached. For TA 102 an increase of about 100 mutants should be reached. Otherwise, the result is evaluated as negative. However, these guidelines may be overruled by good scientific judgment. In case of questionable results, investigations should continue, possibly with modifications, until a final evaluation is possible.
Statistics:
Not specified.

Results and discussion

Test results
Species / strain:
other: TA 98, TA 100, TA 102, TA 1535, TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

The test substance was initially investigated using the Salmonella/microsome plate incorporation test for point mutagenic effects in doses of up to and including 5000 µg per plate on five Salmonella typhimurium LT2 mutants. These comprised the histidine-auxotrophic strains TA 1535, TA 100, TA 1537, TA 98 and TA 102. The independent repeat was performed as preincubation for 20 minutes at 37°C. Other conditions remained unchanged.

Doses up to and including 5000 µg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. Substance precipitation occurred at the dose 158 µg per plate and above.

Evidence of mutagenic activity of teh test substance was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed.

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, mitomycin C, cumene hydroperoxide and 2-aminoanthracene had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to the corresponding negative controls.

Therefore, the test substance was considered to be non-mutagenic without and with S9 mix in the plate incorporation as well as in the preincubation modification of the Salmonella/microsome test.

Applicant's summary and conclusion

Executive summary:

In an Ames test according to OECD TG 471 with the Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 the test material meeting the form described in Section 4.5 of the IUCLID dossier revealed no mutagenic activity in the absence and in the presence of a metabolic activation system.