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Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Mutagenicity in bacteria (OECD 471, Ames): S. typhimurium strains: TA 98, TA 100, TA 102, TA 1535 and TA 1537: Negative with and without metabolic activation

Mutagenicity in mammalian cells: no data

Clastogenicity in mammalian cells: no data

Link to relevant study records
Reference
Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2002-05-13 to 2002-09-19
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
Freie und Hansestadt Hamburg, Behörde für Arbeit, Gesundheit uns SozialesFreie und Hansestadt Hamburg, Behörde für Arbeit, Gesundheit uns Soziales, Germany
Type of assay:
bacterial reverse mutation assay
Target gene:
His operon
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 102
Metabolic activation:
with and without
Metabolic activation system:
Aroclor induced rat liver S9
Test concentrations with justification for top dose:
3.16, 10, 31.6, 100 and 316 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Acetone
- Justification for choice of solvent/vehicle: Solubility properties and relative non-toxicity to bacteria
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
- S9: 10 µg/plate in water for strains TA 1535 and TA 100.
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
-S9: 10 µg/plate in DMSO for strain TA 98
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
-S9: 100 µg/plate in ethanol for strain TA 1537
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
-S9: 1300 µg/plate in DMSO for strain TA 102
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-anthracene amide
Remarks:
+S9: 2 µg/plate in DMSO for strains TA 98, TA 102, TA 1537
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
cyclophosphamide
Remarks:
+S9: 1500 µg/plate in aqua ad iniectabilia for stains TA 100 and TA 1535
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

DURATION

- Preincubation period: 60 minutes

- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3 plates for each test concentration in 2 independent experiments

DETERMINATION OF CYTOTOXICITY

- Method: Background lawn assessment, revertant colony counts
Evaluation criteria:
A result is positive if the number of revertants is significantly increased compared with the solvent control to at least 2-fold of the solvent control for TA 98, TA 100 and TA 102 and 3-fold of the solvent control for TA 1535 and TA 1537 in both experiments.

Positive results have to be reproducible and the histidine independence of the revertants has to be confirmed by streaking on histidine-free agar plates.

Cytotoxicity is defined as a reduction in the number of colonies by >50% compared with the solvent control and/or a sparse background lawn.
Statistics:
MANN and WHITNEY and Spearman’s rank.
Key result
Species / strain:
S. typhimurium, other: TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
316 μg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
316 μg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
COMPARISON WITH HISTORICAL CONTROL DATA: Results were within range of historical control data


Table 2: Dose range-finding study Number of revertants per plate (2 plates)

 

TA100

Conc.
(µg/plate)

Plate 1

Plate 2

Cytotoxic
(yes/no)

0*

148

140

No

0.316

160

151

No

1

148

141

No

3.16

153

149

No

10

138

141

No

31.6

162

149

No

100

132

162

No

316

171

157

Yes

1000

0

0

Yes

3160

0

0

Yes

5000

0

0

Yes

*solvent control with acetone

Table 3: Experiment 1 Plate incorporation Number of revertants per plate (mean of 3 plates)

 

TA98

TA100

TA102

Conc.
µg/plate

MA

+

MA

Cytotoxic
(yes/no)

MA

+

 MA

Cytotoxic
(yes/no)

MA

+

MA

Cytotoxic
(yes/no)

0*

30.3

39

No

152.3

164.7

No

273.7

275.7

No

3.16

34.7

38.3

No

152

159.7

No

275.7

278

No

10

26.3

33.3

No

155

164.3

No

274.3

266

No

31.6

26.7

39

No

149

169

No

270

273

No

100

22.7

36.3

No

152

162

No

270.7

262.7

No

316

31.7

36

Yes

150

164.7

Yes

272.3

260.7

Yes

Positive control

726.3

736.3

No

1091.7

1093.3

No

1105.3

1115

No

*solvent control with acetone

Table 3: Experiment 1 Plate incorporation Number of revertants per plate (mean of 3 plates)

 

TA1535

TA1537

Conc.
µg/plate

MA

+

 MA

Cytotoxic
(yes/no)

MA

+

MA

Cytotoxic
(yes/no)

0*

17.3

17.7

No

4

5

No

3.16

16

15

No

4

3.7

No

10

17.3

18

No

2.7

4

No

31.6

15.7

12

No

3

3.3

No

100

16

17

No

3.7

4.7

No

316

15.3

18.3

Yes

3

4.3

Yes

Positive control

529.3

530.7

No

518.3

528.3

No

*solvent control with acetone

Table 4: Experiment 2 Preincubation Number of revertants per plate (mean of 3 plates)

 

TA98

TA100

TA102

Conc.
µg/plate

MA

+

MA

Cytotoxic
(yes/no)

MA

+

MA

Cytotoxic
(yes/no)

MA

+

 MA

Cytotoxic
(yes/no)

0*

32

35.3

No

151.3

176.7

No

271.7

287.7

No

3.16

31

35

No

136.3

162.3

No

285

260.3

No

10

30.7

36

No

146.7

165

No

278

269.3

No

31.6

25.3

26.7

No

161

171

No

278

268.3

No

100

25

27

No

152

170.7

No

274

271.3

No

316

26.7

32.7

Yes

157

173.3

Yes

277

292

Yes

Positive control

876.7

1062.3

No

1300.3

1264

No

1294.3

1267.3

No

*solvent control with acetone

Table 4: Experiment 2 Preincubation Number of revertants per plate (mean of 3 plates)

 

TA1535

TA1537

Conc.
µg/plate

MA

+ MA

Cytotoxic
(yes/no)

MA

+

MA

Cytotoxic
(yes/no)

0*

15.3

14.7

No

4

3.3

No

3.16

15

12.3

No

3

4

No

10

11.3

12.3

No

2.3

4

No

31.6

12

14.3

No

3.3

4.7

No

100

13.7

12.7

No

3

4

No

316

12

12

Yes

3

4

Yes

Positive control

491.7

451

No

443.3

446.7

No

*solvent control with acetone

MA - Metabolic activation

Conclusions:
Interpretation of results:
negative with metabolic activation
negative without metabolic activation

In a reliable test, conducted under OECD 471, with GLP, no mutagenic effect was observed for the test substance tested up to cytotoxic concentration in any of the test strains in two independent experiments without and with metabolic activation. The test substance is non-mutagenic in test strains used.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

An Ames test is available with dimethoxymethyloctadecylsilane (CAS 70851-50-2).

The mutagenicity of dimethoxymethyloctadecylsilane in bacteria was assessed in a study performed according to OECD Guideline 471 with Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and TA 102 (LPT, 2002). The tester strains were treated using the plate incorporation and the preincubation method both with and without S9-mix. The concentrations tested were 3.16 – 316 µg/plate for the plate incorporation and preincubation test, respectively. Results achieved with vehicle (acetone) and positive controls were valid. No genotoxicity was observed in the presence and absence of metabolic activation. No precipitation was observed up to the highest dose tested. Cytotoxicity (defined as reduction of colonies by more than 50% and/or by a scarce background lawn) was observed in all strains at 316 µg/plate. In conclusion, dimethoxymethyloctadecylsilane did not induce mutations in bacteria under the test conditions applied.


Justification for classification or non-classification

The available in vitro data are reliable and suitable for classification and fulfil the standard requirements given in Annex VII of Regulation (EC) 1272/2008. Based on the available data, there is no indication that the substance induces genetic toxicity. Nevertheless, no final decision on classification for genetic toxicity according to Regulation (EC) 1272/2008 or Directive 67/548/EEC can be made, as no information on mutagenicity and clastogenicity in mammalian cells/in vivo is available.