Morpholine, 4-[(triethoxysilyl)methyl]-

Genetic toxicity: in vitro

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:

2005-04-25 to 2005-07-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD test under GLP

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 21st July 1997

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

480-370-1

EC Name:

-

Cas Number:

21743-27-1

Molecular formula:

Hill formula: C11H25NO4Si CAS formula: C11H25NO4Si

IUPAC Name:

4-[(triethoxysilyl)methyl]morpholine

Method

Target gene:

strain specific loci for the histidin gene.

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 102

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9 liver microsomal fraction of phenobarbital and beta-naphthoflavone induced rats.

Test concentrations with justification for top dose:

Concentrations in the main test (with metabolic activation): 31.6, 100, 316, 1000, 2500 and 5000 µg/plate
Concentrations in the main test (without metabolic activation): 31.6, 100, 316, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The solvent was compatible with the survival of the bacteria and the S9 activity.

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 1537, TA 100 without S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 4-Nitro-o-phenylene-diamine

Remarks:

TA 1537, TA 98 without activation

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

TA 102 without activation

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

all strains with activation

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- Standard plate test and preincubation test

DURATION
- Exposure duration: at least 48 h

NUMBER OF REPLICATES:
- Three replicates for each concentration/test compound

DETERMINATION OF CYTOTOXICITY
Toxicity detected by a
• decrease in the number of revertants
• clearing or diminution of the background lawn (= reduced his- or trp- background growth)
is recorded for all test groups both with and without S9 mix in all experiments and indicated in
the tables.

Evaluation criteria:

Acceptance criteria
Generally, the experiment is considered valid if the following criteria are met:
• The number of revertant colonies in the negative controls was within the range of the
historical negative control data for each tester strain.
• the bacteria demonstrated their typical responses to crystal violet and ampicillin.
• corresponding background growth on both negative control and test plates was observed.
• The positive control substances both with and without S9 mix induced a distinct increase in
the number of revertant colonies within the range of the historical positive control data or
above.


Assessment criteria
The test chemical is considered positive in this assay if the following criteria are met:
• A clear and dose-related increase in the number of revertant occurs and/or a reproducible biologically relevant positive response for at least one of the dose groups occurs in at least one tester strain with or without metabolic activation.
A biologically relevant increase is described as follows:
• if in tester strains TA 100 and TA 102 the number of reversions is at least twice as high
• if in tester strains TA 98, TA 1535 and TA 1537 the number of reversions is at least three times higher
as compared to the spontaneous reversion rate.

Statistics:

A statistical evaluation of the results is not regarded as necessary.

Results and discussion

Test results

Test results 1

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:

cytotoxicity

Remarks:

in strain TA 1535 at a dose of 2500 µg/plate and higher (with metabolic activation) and in strain TA 1537 at a dose of 5000 µg/plate (with metabolic activation), both in the pre-incubation test only.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

in strain TA 102 at a dose of 5000 µg/plate (with metabolic activation) in the pre-incubation test only.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No precipitation of the test item in the solvent (DMSO) was observed.

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

The tested substance did not induce back mutations at the respective histidine gene loci of the used tester strains (TA 98, TA 100, TA 1535, TA 1537 and TA 102) with and without metabolizing activation.

Executive summary:

The test item N-(Morpholinomethyl)triethoxysilane was investigated for its potential to induce gene mutations according to the plate incorporation and the pre-incubation test using Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and TA 102. The study followed the OECD Guideline 471 (1997). The assay was performed in two independent experiments both with and without metabolic activation. The concentrations covered the range from 31.6 to 5000 µg/plate. No relevant toxic effects occured in the plate incorporation test. In the pre-incubation test toxic effects of the test item were observed in tester strain TA 1535 at a dose of 2500 µg/plate and higher (with metabolic activation) and in tester strains TA 1537 and TA 102 at a dose of 5000 µg/plate (with metabolic activation). No substantial increase in revertant colony numbers were observed in any experiment with the test substance. Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies. In conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test article did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore SLM 449020 is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.