2-Oxa-7-thia-3,8-disiladecane, 3-methoxy-3,8,8,9,9-pentamethyl-

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Conducted at GLP-accredited facility to current guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

10% rat liver S9

Test concentrations with justification for top dose:

0, 50, 150, 500, 1500, 5000 µg/plate

Vehicle / solvent:

DMSO - test material miscible

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Controls 2

Positive controls:

yes

Positive control substance:

N-ethyl-N-nitro-N-nitrosoguanidine

Remarks:

without activation

Controls 3

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

without activation

Controls 4

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

without activation

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

with activation

Controls 6

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

with activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)


DURATION
- Preincubation period: none
- Exposure duration: 48 hours


NUMBER OF REPLICATIONS: 2 experiments, with each strain/concentration performed in triplicate with/without activation


DETERMINATION OF CYTOTOXICITY
- Method: background lawn

ACCEPTANCE CRITERIA
All tester strains exhibit a characteristic number of spontaneous revertants in the vehicle and controls
Appropriate characteristics for each tester strain confirmed
All tester strain cultures in the range 1-9.9x10^9 bacteria per ml
Each mean positive control should be at least two-fold higher than the vehicle control
A minimum of 4 non-toxic test material concentrations
No evidence of excessive contamination

Evaluation criteria:

Dose-related increase in revertants over the concentration range or a reproducible increase at one or more concentrations in at least one strain with or without activation
Biological relevance considered first, with statistical methods used as an aid to evaluation but not the only factor in determining a positive response

Statistics:

As recommended by UKEMS

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:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

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

Untreated negative controls validity:

not applicable

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:

The test material was not mutagenic to any tester strain, eitther in the presence or absence of metabolic activation, up to the recommended limit concentration.