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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: Guideline study and GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
- Name: Carbamic acid, N-(3-(triethoxysilyl)propyl)2-(ethyl-(4-nitrosophenyl) amino) ethyl ester
- CAS 1195231-94-7
- Batch 3445-60
- Purity 95 %

Method

Target gene:
not applicable
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Rat liver S9 Mix induced by phenobarbital and ß-naphthoflavone
Test concentrations with justification for top dose:
- 1. Test: 10 to 3330 ug/plate (absence of S9)
- 1. Test: 33 to 5000 ug/plate (presence of 5% S9, strains TA 1535, TA 1537, TA 98)
- 2. Test: up to 3330 ug/plate (TA 1535, TA 98, -S9) and up to 5000 ug/plate (TA 1535, TA 98, + 10% S9)
- 2. Test: up to 1000 ug/plate (TA 1537, TA 100, -S9) and up to 3330 ug/plate (TA 1537, TA 100, + 10% S9)
- 2. Test: up to 5000 ug/plate (WP2uvrA, -S9/+ 10% S9)
Vehicle / solvent:
Ethanol
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
2-nitrofluorene
sodium azide
methylmethanesulfonate
other: 2-aminoanthracene
Evaluation criteria:
A test substance is considered negative (not mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 is not greater than two times the concurrent control, and the total number of revertants in tester
strains TA1535, TA1537. TA98 or WPuvrA is not greater than three times the concurrent control.
b) The negative response should be reproducible in at least one independently repeated experiment.

A test substance is considered positive (mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 is greater than two times the concurrent control, or the total number of revertants in tester strains
TA 1535, TA 1537, TA95 or WPuvrA is greater than three times the concurrent control.
b) In case a repeat experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one independently repeated experiment.

The preceding criteria were not absolute and other modifying factors might enter into the final evaluation decision.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Remarks on result:
other: strain/cell type: S.taphimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2uvr A
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

EXPERIMENT 1

Precipitation was observed at the start of the incubation period at concentrations of 3330 ug/plate and upwards and at 5000 ug/plate at the end of the incubation period.

Reduction of the bacterial background lawn was moderate to extreme and microcolonies were observed.

No increase in the number of revertants was observed upon treatment with the test item under all conditions tested.

EXPERIMENT 2

Precipitation was observed at the start of the incubation period at concentrations of 3330 ug/plate and upwards and at 5000 ug/plate at the end of the incubation period.

Reduction of the bacterial background lawn was normal to moderate to extreme and microcolonies were observed.

No increase in the number of revertants was observed upon treatment with the test item under all conditions tested.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

All bacterial strains showed negative responses over the entire dose range, i.e. no significant dose-related increase in the number of revertants in two independently repeated experiments.
The negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

Based on the results of this study it is concluded that test item 3445-60 is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.
Executive summary:

SUMMARY

Evaluation of the mutagenic activity of 3445-60 in the Salmonella typhimurium reverse mutation assay and the Escherichia coli reverse mutation assay (with independent repeat)

Test item 3445-60 was tested in the Salmonella typhimurium reverse mutation assay with four histidine requiring strains of Salmonella typhimurium (TA1535, TA1537, TA98 and TA100) and in the Escherichia coli reverse mutation assay with a tryptophan-requiring strain of Escherichia coli (WP2uvrA). The test was performed in two independent experiments in the presence and absence of S9-mix (rat liver S9-mix induced by a combination of phenobarbital and ß-naphthoflavone). The study procedures described in this report were based on the most recent OECD and EC guidelines.

3445-60 was a green powder with lumps with a purity of 95%. The test substance was dissolved in ethanol. In the dose range finding test, 3445-60 was tested up to concentrations of 5000 µg/plate in the absence and presence of S9-mix in the strains TA 100 and WP2uvrA 3445-60 precipitated on the plates at the top dose level of 5000 µg/plate. Cytotoxicity was observed in both tester strains.

Based on the results of the dose range finding test, 3445-60 was tested in the first mutation assay at a concentration range of 10 to 3330 µg/plate in the absence of S9-mix and at a concentration range of 33 to 5000 µg/plate in the presence of 5% (v/v) S9-mix in tester strains TA 1535, TA 1537 and TA98. Cytotoxicity was observed in all three tester strains. In an independent repeat of the assay with additional parameters, 3445-60 was tested in the absence and presence of 10% (v/v) S9-mix in tester strains TA1535, TA1537, TA98, TA100 and WP2uvrA. Cytotoxicity was observed in all tester strains.

3445-60 did not induce a significant dose-related increase in the number of revertant (His') colonies in each of the four tester strains (TA 1535, TA 1537, TA98 and TA 100) and in the number of revertant (Trp') colonies in tester strain WP2uvrA both in the absence and presence of S9-metabolic activation. These results were confirmed in an independently repeated experiment. In this study, the negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.