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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

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
mutant histidine gene
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
Metabolic activation:
with and without
Metabolic activation system:
S9 mix was made from the livers of male Sprague Dawley rats, which received a single intraperitoneal injection of 500 mg/kg bw Aroclor 1254, dissolved in corn oil, 5 days prior to sacrifice. The S9 mix comprised 10% S9 fraction.
Test concentrations with justification for top dose:
plate incorporation assay:
0, 50, 160, 500, 1600, 5000 µg/plate with and without S9 mix
preincubation assay:
0, 50, 160, 500, 1600, 5000 µg/tube with and without S9 mix
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: deionized water (positiv control Mitomycin C); DMSO (test item and other positive controls)
- Justification for choice of solvent/vehicle: test item formed a yellowish clear solution
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Remarks:
-S9: Na-azide (only TA 1535), nitrofurantoin (only TA 100), 4-nitro-1,2-phenylene diamine (TA 1537 and TA 98), mitomycin C (only TA 102 in plate incorporation assay), cumene hydroperoxide (only TA 102 in preincubation assay): + S9: 2-aminoanthracene
Details on test system and experimental conditions:
- Composition of test material, percentage of components: 100%
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:
no statistics perfomed; evaluation based on criteria mentioned above

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102
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
Positive controls validity:
valid
Additional information on results:
Test item precipitation occurred at 5000 µg per plate/tube. No bacteriotoxic effects were produced up to 5000 µg/plate in the plate incorporation test. In the preincubation assay bacteriotoxic effects were observed at 5000 µg/tube only in TA 1537.
No indication of mutagenic effects could be found for the test item at doses of up to 5000 µg per plate in any of the Salmonella typhimurium strains used, without and with metabolic activation, under the experimental conditions applied.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Executive summary:

The test item was evaluated in an Ames Test on Salmonella typhimurium strains TA 1535, TA 100, TA, 1537, TA 98, and TA 102, performed according to OECD TG 471. Doses of up to and including 5000 µg per plate did not produce bacteriotoxic effects. Substance precipitation occurred at 5000 µg per plate. The test material 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. Positive controls increased the mutant counts to well over those of the negative controls, thus demonstrated the system´s sensitivity.