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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1998-11-10 - 1998-11-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
his and trp operon
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli, other: E coli WP2 trp pKM101 (CM881)
Species / strain / cell type:
E. coli, other: E coli WP2 trp uvrA pKM101 (CM891)
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced rat liver S9
Test concentrations with justification for top dose:
50, 150, 500, 1500 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: Sponsors choice as completely miscible in water
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene: with metabolic activation: 2 µg/plate TA1535, 10 µg/plate CM881 and CM891
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
TA1537, TA98 and TA100 with metabolic activation Migrated to IUCLID6: 5 µg/plate
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation); preincubation

ACTIVATION: S9 mix contained S9 fraction 10%, MgCl, KCl, sodium orthophosphate buffer pH 7.4, glucose-6-phosphate and NADP. 0.5 ml S9 mix and 0.1ml of test solution were added to 2ml agar.

DURATION

- Preincubation period: 30 minutes
- Exposure duration: 3 days

SELECTION AGENT (mutation assays): histidine deficient agar

NUMBER OF REPLICATIONS: triplicate plates, experiment repeated

DETERMINATION OF CYTOTOXICITY
- Method: other: condition of background lawn

ACTIVATION
- Aroclor induced rat liver S9 was present at 10% in the S9 mix, which included NADP and glucolse-6-phosphate as cofactors. 0.5 ml S9 mix was added to 2 ml top agar, 0.1 ml test solution or control and 0.1 ml bacterial culture giving a final concentration of approximately 2%.
Evaluation criteria:
A result is considered positive if there is a three-fold increase in the number of revertants in TA1535, TA1537 and TA98 over the solvent control and a two-fold increase for other strains. This should occur in both experiments and show some evidence of a dose-relationship. The positive controls must cause at least a doubling of mean revertant colony numbers over the mean of the solvent control.
Statistics:
None in report

Results and discussion

Test resultsopen allclose all
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:
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
Species / strain:
E. coli WP2 uvr A pKM 101
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
Species / strain:
E. coli, other: E. coli WP2 pKM101 (CM881)
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 valid
Positive controls validity:
valid

Any other information on results incl. tables

Average number of revertants per plate (mean of three plates)

Treatment µg/plate

TA 1535

TA 1537

TA 98

TA 100

CM 881

CM 891

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent control

  14

 16

  9

10

 19

 23

108

127

 46

 53

 179

  180

   50

 14

 19

  7

  6

 22

 27

110

133

 56

 67

 201

  190

 150

 14

 20

  7

   7

 19

 24

111

132

 63

 77

 189

  203

 500

 14

 16

  7

   8

 24

 24

109

113

 46

 56

 193

  203

1500

 13

 16

  6

   7

 25

 23

111

123

 61

 73

 199

  195

5000

 10

 11

  9

   9

 15

 23

 87

114

 61

 63

 188

  197

Positive control

370

179

316

46

115

164

456

718

817

392

1703

1799

Average Revertants per plate with and without metabolic activation – Exp 2 pre-incubation

 

Treatment µg/plate

TA 1535

TA 1537

TA 98

TA 100

CM 881

CM 891

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

Solvent control

 18

 15

   9

   9

 29

 27

134

143

 61

 69

 247

242

   50

 20

 16

   8

 11

 27

 31

115

134

 55

 73

 238

253

 150

 18

 18

   9

 10

 21

 30

110

135

 47

 66

 216

237

 500

 13

 21

 10

   9

 26

 26

106

129

 58

 62

 261

253

1500

 18

 18

  7

   8

 21

 28

113

114

 54

 80

 230

235

5000

 15

 18

  8

   6

 25

 28

105

 97

 48

 60

 215

268

Positive control

244

115

120

144

130

270

456

569

792

438

1569

758

Average Revertants per plate with and without metabolic activation – Exp 1

Applicant's summary and conclusion

Conclusions:
N-(3-(trimethoxysilyl)propyl)ethylenediamine has been tested for mutagenicity to bacteria, in a study that was conducted according to the OECD TG 471 and in compliance with GLP. No evidence of test substance related increase in the number of revertants was observed with or without activation in the initial experiment using the plate incorporation method or the repeat pre-incubation assay in Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537, E coli WP2 trp uvrA pKM101 (CM891) and E coli WP2 trp pKM101 (CM881). The solvent used was water, and hydrolysis was likely to have occurred under test conditions, so it is assumed that exposure was to the hydrolysis product as well as the parent substance. It is not considered to invalidate the study, as it is considered that hydrolysis may occur in vivo. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.