Dichloromethyloctadecylsilane

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dichloromethyloctadecylsilane

EC Number:

225-931-1

EC Name:

Dichloromethyloctadecylsilane

Cas Number:

5157-75-5

Molecular formula:

C19H40Cl2Si

IUPAC Name:

dichloromethyloctadecylsilane

Test material form:

liquid

Specific details on test material used for the study:

Purity 90,9%

Method

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:

Aroclor 1254

Test concentrations with justification for top dose:

31.6, 100, 316, 1000 and 3160 µ/plate

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

In conclusion, under the present test conditions Silan ODM tested up to cytotoxic
concentrations caused no mutagenic effect in the Salmonella typhimurium strains
TA 98, TA 100, TA 102, TA 1535 and TA 1537 neither in the plate incorporation test
nor in the preincubation test each carried out without and with metabolic activation.

Executive summary:

Silan ODM was examined in the 5 Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in two independent experiments, each carried out without and with metabolic activation (a microsomal preparation derived from Aroclor 1254 induced rat liver). The first experiment was carried out as a plate incorporation test and the second as. a preincubation test. Preliminary test Silan ODM was examined in a preliminary cytotoxicity test without metabolic activation in test strain TA 100. Ten concentrations ranging from 0.316 to 5000 µg/plate were tested. Cytotoxicity (reduction of the number of revertants by more than 50%) and test substance precipitation were noted at concentrations of 31 60 and 5000 µg Silan ODM/plate. Hence, 3160 µg/plate was chosen as the top concentration for the main study. Main study Five (5) concentrations ranging from 31.6 to 3160 µg Silan ODM/plate were employed in two independent experiments each carried out without and with metabolic activation. Cytotoxicity In both experiments (plate incorporation test or preincubation test) cytotoxicity (reduction of the number of revertants by more than 50%) was noted at the top concentration of 3160 JIg Silan ODM/plate in all test strains in both experiments carried out without and with metabolic activation. Mutagenicity No mutagenic effect (no increase in revertant colony numbers as compared with control counts) was observed for Silan ODM tested up to a concentration of 3160 µg/plate in any of the 5 test strains in two independent experiments without and with metabolic activation (plate incorporation or preincubation test).